VSCOM netcom 123, netcom 823RM, netcom 423, netcom 1623RM User Manual

VS NetCom Wireless Serial
Device Server
WLAN Versions User Manual
NetCom 123, 423, 823RM and 1623RM
1.1. TABLE OF CONTENTS
1.
TABLES.................................................................. 1
1.1. TABLE OF CONTENTS ..................................................... 1
1.2. TABLE OF IMAGES........................................................... 6
1.3. TABLE OF TABLES ......................................................... 10
2. INTRODUCTION ..................................................11
2.1. FEATURES......................................................................... 11
2.2. PRODUCT SPECIFICATIONS ....................................... 12
2.2.1. Common Characteristics............................................... 12
2.2.2. Specific Characteristics ................................................ 13
2.2.2.1. NetCom 123 WLAN............................................. 13
2.2.2.2. NetCom 423 WLAN............................................. 13
2.2.2.3. NetCom 823RM WLAN (19” version) ............... 13
2.2.2.4. NetCom 1623RM WLAN (19” version) .............. 13
2.3. PACKING LIST ................................................................. 13
3. HARDWARE CONFIGURATION .........................14
3.1. POWER SUPPLY............................................................... 14
3.2. NETWORK......................................................................... 14
3.2.1. WLAN Antenna............................................................ 14
3.2.2. WLAN Configuration................................................... 14
3.2.3. Ethernet......................................................................... 15
3.3. SERIAL PORT SIMPLE SETTINGS.............................. 15
4. WINDOWS DRIVER QUICK INSTALLATION ..... 16
4.1. INSTALLATION PROCEDURE ..................................... 16
4.1.1. Start the Installation Wizard ......................................... 16
4.1.2. Find and configure NetCom Devices ........................... 17
4.1.2.1. Configure IP Parameters....................................... 18
4.1.2.2. Configure Firewall................................................ 18
4.1.3. Install Drivers ............................................................... 19
4.2. VERIFY THE INSTALLATION...................................... 20
4.3. UNINSTALL THE DRIVERS .......................................... 22
5. SOFTWARE CONFIGURATION .......................... 23
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5.1. CONFIGURE IN WEB-INTERFACE ............................. 25
5.1.1. Webbrowser Server Configuration............................... 26
5.1.1.1. Server Info ............................................................ 26
5.1.1.2. Server Parameter................................................... 27
5.1.1.3. Wireless Parameter ............................................... 28
5.1.1.4. Encrypted Communication ................................... 29
5.1.1.5. Authentification .................................................... 31
5.1.1.6. Date & Time ......................................................... 31
5.1.2. Webbrowser Serial Port Configuration ........................ 32
5.1.2.1. Serial Settings ....................................................... 32
5.1.2.2. Transfer Settings................................................... 34
5.1.2.2.1. Driver Mode................................................................34
5.1.2.2.2. TCP Raw Server .........................................................34
5.1.2.2.3. TCP Raw Client..........................................................35
5.1.2.2.4. Null Modem Tunnel....................................................36
5.1.2.2.5. IP-Modem ...................................................................36
5.1.2.2.6. TCP Advanced Settings ..............................................37
5.1.2.2.7. UDP Data Transfer .....................................................37
5.1.2.2.8. Print Server Function ..................................................38
5.1.3. Webbrowser NetCom Tools ......................................... 38
5.1.3.1. Ping....................................................................... 39
5.1.3.2. Statistics................................................................ 39
5.1.3.3. Netstat................................................................... 40
5.1.3.4. Wireless ................................................................ 41
5.1.3.5. Firmware............................................................... 42
5.1.3.6. Save and Load Configuration ............................... 42
5.1.3.7. Logging and Debug .............................................. 42
5.2. CONFIGURE WITH MANAGER PROGRAM ............. 43
5.2.1. Starting NetCom Manager............................................ 44
5.2.2. NetCom Server Settings - Info ..................................... 45
5.2.3. NetCom Server Settings - Ports.................................... 46
5.2.4. NetCom Server Settings - Firewall............................... 47
5.2.5. NetCom Server Settings – Options............................... 48
5.2.6. Manual Detection/Installation of a NetCom................. 49
5.2.7. Firewall Traversal Configuration ................................. 49
5.2.7.1. SOHO Firewall example ...................................... 49
5.2.7.2. SOHO Virtual Servers .......................................... 50
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5.2.7.3. NetCom Detection through SOHO Firewall ........ 51
5.2.7.4. Serial Ports through SOHO Firewall .................... 52
5.2.7.5. DMZ and Virtual Servers ..................................... 53
5.2.8. Dynamic IP Address and OpenVPN™......................... 53
5.3. CONFIGURE NETCOM VIA TELNET CONSOLE..... 54
5.3.1. Telnet Main Menu ........................................................ 55
5.3.2. Server Configuration Menu .......................................... 56
5.3.2.1. Parameter .............................................................. 56
5.3.2.2. Wireless ................................................................ 57
5.3.2.3. Encrypted Communication ................................... 58
5.3.2.4. Authentication ...................................................... 61
5.3.2.5. Date & Time ......................................................... 61
5.3.2.6. Info........................................................................ 62
5.3.3. Serial Ports Menu ......................................................... 63
5.3.3.1. Communication Parameters.................................. 63
5.3.3.2. Data Transfer Modes ............................................ 65
5.3.3.2.1. Driver Mode................................................................67
5.3.3.2.2. TCP Raw Server Mode ...............................................67
5.3.3.2.3. TCP Raw Client Mode................................................68
5.3.3.2.4. Null Modem Tunnel....................................................68
5.3.3.2.5. IP Modem....................................................................69
5.3.3.2.6. UDP Mode ..................................................................69
5.3.3.2.7. Print Server Function ..................................................70
5.3.4. Tools Menu................................................................... 70
5.3.4.1. Ping....................................................................... 70
5.3.4.2. Statistics................................................................ 71
5.3.4.3. Netstat................................................................... 71
5.3.4.4. Wireless ................................................................ 72
5.3.4.5. Logging................................................................. 73
5.3.4.6. Firmware............................................................... 73
5.3.5. Save&Exit Menu .......................................................... 74
5.3.5.1. Save Parameter ..................................................... 74
5.3.5.2. Exit........................................................................ 74
5.3.5.3. Reboot................................................................... 74
5.4. CONFIGURE NETCOM VIA SERIAL CONSOLE ...... 75
6. THE VIRTUAL COM DRIVER ..............................76
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6.1. INSTALLATION OF NETCOM SERVERS................... 76
6.1.1. Changing the Installation.............................................. 78
6.2. CONFIGURE THE SERIAL PORTS .............................. 79
6.3. PERFORMANCE ISSUES................................................ 80
6.4. NETWORK & MISC PROPERTIES............................... 81
6.5. REMOTE SETTINGS PROPERTIES............................. 83
7. UNINSTALLING THE SOFTWARE .....................85
8. SPECIAL FUNCTIONALITIES ............................. 87
8.1. IP MODEM FUNCTION................................................... 87
8.1.1. Some Possible Scenarios: ............................................. 87
8.1.2. Serial signals and cables ............................................... 88
8.1.3. Operation Modes by IP Modem ................................... 89
8.1.4. Hayes commands.......................................................... 89
8.1.4.1. AT command set................................................... 89
8.1.4.1.1. Standard AT-Commands.............................................90
8.1.4.1.2. Extended AT-Commands............................................90
8.1.4.1.3. Non-AT commands.....................................................91
8.1.4.2. S-Registers for Configuration............................... 91
8.1.4.3. Sample Commands used by Windows ................. 92
8.1.5. Description of AT-Commands ..................................... 92
8.1.5.1. AT D (dial) ........................................................... 92
8.1.5.2. AT O (online / data mode).................................... 93
8.1.5.3. AT A (answer call) ............................................... 93
8.1.5.4. AT B (modulation) [ATB1]................................ 93
8.1.5.5. AT E (echo) [ATE1]........................................... 93
8.1.5.6. AT Q (quiet) [ATQ0] .......................................... 93
8.1.5.7. AT V (verbose) [ATV1] ...................................... 94
8.1.5.8. AT H (hangup) [ATH0]....................................... 94
8.1.5.9. AT I(n) (information) [ATI0] .............................. 94
8.1.5.10. AT S (setup).......................................................... 94
8.1.5.11. AT L (loudness).................................................... 95
8.1.5.12. AT M (speaker) .................................................... 95
8.1.5.13. AT N (auto baud) ATN0 ..................................... 95
8.1.5.14. AT Z (reset) .......................................................... 95
8.1.5.15. AT &F (factory settings) [AT&F0] ..................... 95
8.1.5.16. AT &C (DCD configuration) [AT&C1].............. 95
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8.1.5.17. AT &S (DSR configuration) [AT&S0] ............... 95
8.1.5.18. AT &D (DTR configuration) [AT&D2].............. 96
8.1.5.19. AT &K (handshake) [AT&K3] AT \Q [AT\Q3] 96
8.1.5.20. AT &V (view profile)........................................... 96
8.1.5.21. AT &W (save profile)........................................... 96
8.1.5.22. AT &Z (save destination) ..................................... 96
8.2. PRINT SERVER OPERATION ....................................... 97
8.2.1. Printer Queue................................................................ 97
8.2.2. Printer Reset ................................................................. 98
8.2.2.1. Init String Definition ............................................ 98
8.2.2.1.1. ASCII Text..................................................................98
8.2.2.1.2. ASCII Control Codes..................................................98
8.2.2.1.3. Numeric Codes............................................................98
8.2.2.1.4. Modem Control Signals..............................................98
8.2.2.1.5. Timing Options...........................................................99
8.2.2.2. Reset Example ...................................................... 99
8.2.3. Operation in Windows
®............................................... 99
8.2.3.1. Add a New Printer ................................................ 99
8.2.3.1.1. Create new printer port .............................................100
8.2.3.1.2. Name the new Printer Port........................................101
8.2.3.1.3. Configure the Printer Port.........................................101
8.2.3.1.4. Install Printer Driver .................................................102
8.2.3.2. Modify an Existing Printer ................................. 102
8.2.3.2.1. Open the properties...................................................103
8.2.3.2.2. Add the Print Server Port..........................................103
8.3. OPENVPN™ ENCRYPTION ......................................... 104
8.3.1. OpenVPN™ Installation............................................. 104
8.3.2. NetCom OpenVPN Configuration.............................. 106
8.3.3. OpenVPN™ Configuration ........................................ 106
8.3.3.1. OpenVPN Configuration File............................. 107
8.3.3.2. Start OpenVPN™ by Context-Menu.................. 108
8.3.3.3. Start OpenVPN™ by Command line ................. 109
8.3.3.4. Start OpenVPN™ as Windows Service ............. 110
8.3.4. OpenVPN without Encryption.................................... 111
8.3.5. Reconfigure Virtual Serial Ports for OpenVPN™ ..... 112
9. TCP/IP DESCRIPTION....................................... 113
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9.1. RECOMMENDED SETTINGS ...................................... 113
9.1.1. Static Configuration.................................................... 113
9.1.2. DHCP Configuration .................................................. 113
9.1.3. Automatic Configuration (APIPA)............................. 114
9.1.4. Other Configuration.................................................... 114
10. HARDWARE DETAILS ......................................115
10.1. SERIAL PORT CONFIGURATION ......................... 115
10.2. SIGNAL ASSIGNMENT ............................................. 116
10.3. RS422/485 ELECTRICAL CONFIGURATION....... 117
10.3.1. Termination Resistors................................................. 117
10.3.2. BIAS Function............................................................ 117
10.4. VIEWS OF NETCOM ................................................. 118
10.4.1. NetCom 123 WLAN................................................... 118
10.4.2. NetCom 423 WLAN................................................... 119
10.4.3. NetCom 823RM WLAN ............................................ 120
10.4.4. NetCom 1623RM WLAN .......................................... 120
11. TROUBLESHOOTING GUIDE ........................... 121
12. GLOSSARY OF TERMS ....................................124
1.2. TABLE OF IMAGES
Master Switch Standard Configuration ................................................ 15
Installation Wizard ............................................................................... 16
Start Driver Installation ........................................................................ 16
Discover and Select NetCom Devices for Installation ......................... 17
NetCom in Manager ............................................................................. 17
Define NetComs IP Configuration ....................................................... 18
Use current drivers dialog..................................................................... 19
Install drivers for the serial ports.......................................................... 20
VScom drivers in the Start Menu ......................................................... 20
NetCom in Device Manager ................................................................. 21
NetCom Manager NT ........................................................................... 21
Uninstall NetCom Drivers .................................................................... 22
NetCom Manager ................................................................................. 23
NetCom Manager Servers Panel........................................................... 24
NetCom IP-Parameters......................................................................... 24
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Webinterface for configuration ............................................................ 25
Webinterface Request to Reboot .......................................................... 25
Web Panel Server Information ............................................................. 26
Web Panel Server Parameter ................................................................ 27
Web Panel Wireless Parameter............................................................. 28
Web Panel OpenVPN Network Parameter........................................... 30
Web Panel OpenVPN Encryption grades............................................. 30
Web Panel OpenVPN Key Configuration ............................................ 30
Web Panel Authentification.................................................................. 31
Web Panel Date & Time....................................................................... 31
Web Panel Serial Settings..................................................................... 32
Web Panel Op-Mode by Software........................................................ 32
Web Panel Advanced Flow Control ..................................................... 33
Web Panel Serial Port Mode Selection................................................. 34
Web Panel Driver Mode ....................................................................... 34
Web Panel TCP Raw Server................................................................. 34
Web Panel Raw Client.......................................................................... 35
Web Panel Null Modem Tunnel........................................................... 36
Web Panel IP-Modem .......................................................................... 36
Web Panel TCP Advanced Settings ..................................................... 37
Web Panel UDP Data Transfer............................................................. 37
Web Panel Print Server Configuration ................................................. 38
Web Panel Ping .................................................................................... 39
Web Panel Statistics Port Selection...................................................... 39
Web Panel Port Statistics...................................................................... 39
Web Panel Start Netstat........................................................................ 40
Web Panel Netstat Output .................................................................... 40
Web Panel WLAN Scan ....................................................................... 41
Web Panel WLAN Scan Output........................................................... 41
Web Panel Firmware Upload ............................................................... 42
Web Panel Save/Load Configuration ................................................... 42
Web Panel Syslog & Debug ................................................................. 42
NetCom Manager ................................................................................. 43
NetCom Manager in Start Menu .......................................................... 43
NetCom Manager in Device Manager.................................................. 43
NetCom Manager “Servers” Panel ....................................................... 44
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NetCom Manager Server Settings ........................................................ 45
NetCom Manager Ports Panel .............................................................. 46
NetCom Manager Firewall Panel ......................................................... 47
NetCom Manager Options Panel.......................................................... 48
NetCom Manager Firewall Panel ......................................................... 51
NetCom Manager Port Configuration for Driver ................................. 52
Telnet Password protected option......................................................... 54
Telnet Open configuration menu.......................................................... 54
Telnet Main menu configuration console............................................. 55
Telnet Server Configuration ................................................................. 56
Telnet IP-Configuration Parameters..................................................... 56
Telnet Wireless Configuration.............................................................. 57
Telnet Wireless Configuration Parameter ............................................ 57
Telnet Wireless Configuration.............................................................. 58
Telnet OpenVPN Configuration Parameter.......................................... 59
Telnet OpenVPN Encryption................................................................ 59
Telnet Sample OpenVPN Key.............................................................. 60
Telnet use new Key .............................................................................. 60
Telnet Access Authentication............................................................... 61
Telnet Password Dialog........................................................................ 61
Telnet Date & Time.............................................................................. 61
Telnet Date and Time Retrieval options............................................... 61
Telnet Information................................................................................ 62
Telnet NetCom Server Information...................................................... 62
Telnet Menu, select serial port for configuration ................................. 63
Telnet Configure Communication Parameters ..................................... 63
Telnet Serial transfer parameters.......................................................... 63
Telnet Op-Mode by Software ............................................................... 63
Telnet Standard Flow Controls............................................................. 64
Telnet Advanced Flow Control configuration...................................... 64
Telnet Configure Data Transfer Mode (TCP/IP).................................. 65
Telnet TCP-Ports for Driver and Raw mode ........................................ 65
Telnet Available Transfer Modes ......................................................... 65
Telnet Parameters for transfer modes................................................... 66
Telnet Driver Mode parameters............................................................ 67
Telnet TCP Raw Server parameters ..................................................... 67
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Telnet TCP Raw Client parameters ...................................................... 68
Telnet Null Modem Tunnel parameters................................................ 68
Telnet IP Modem Parameters ............................................................... 69
Telnet UDP Mode parameters .............................................................. 69
Telnet Print Server Configuration ........................................................ 70
Telnet Tools menu ................................................................................ 70
Telnet Ping test utility........................................................................... 70
Telnet Statistics for serial ports ............................................................ 71
Telnet Status and Statistics ................................................................... 71
Telnet Netstat analysis.......................................................................... 71
Telnet Sample Netstat output ............................................................... 71
Telnet Tools Wireless Option............................................................... 72
Telnet Sample WLAN Scan Output ..................................................... 72
Telnet Syslog Option ............................................................................ 73
Telnet Syslog configuration.................................................................. 73
Telnet Firmware Update....................................................................... 73
Telnet Settings, Firmware Update via TCP/IP ..................................... 73
Telnet Save current Parameters ............................................................ 74
Telnet Exit from configuration ............................................................. 74
Telnet Exit and Reboot ......................................................................... 74
Select NetCom to install ....................................................................... 76
Excluded NetCom................................................................................. 77
NetCom Manager Ports View............................................................... 77
Reconfigured NetCom found................................................................ 78
Replaced NetCom found ...................................................................... 78
NetCom COM Port Serial Settings....................................................... 79
NetCom COM Port Performance Settings............................................ 80
NetCom COM Port Network & Misc Properties.................................. 81
NetCom COM Port Remote Settings Properties .................................. 83
Uninstall in Control Panel -> Add/Remove programs ......................... 85
Uninstall in the Start Menu................................................................... 85
Confirm Uninstall of Drivers................................................................ 85
Installation Wizard to uninstall Drivers................................................ 86
Add a printer......................................................................................... 99
Select Printer Port.............................................................................. 100
Create Printer Port .............................................................................. 100
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Properties of Print Server Port............................................................ 101
Properties of Print Server Port............................................................ 102
Printer Port Properties ........................................................................ 103
Add Printer Port.................................................................................. 103
OpenVPN Installation Wizard............................................................ 104
OpenVPN Installable Components..................................................... 105
Installing TAP-Win32 Adapter .......................................................... 105
OpenVPN Network Adapter............................................................... 105
OpenVPN Configuration File............................................................. 107
Context-Menu of OpenVPN™ ........................................................... 108
OpenVPN Connection is active.......................................................... 109
OpenVPN by Command line.............................................................. 109
OpenVPN as Windows Service.......................................................... 110
Start OpenVPN Service ...................................................................... 111
Service Options................................................................................... 111
Startup Types...................................................................................... 111
RS422/485 Jumper ............................................................................. 117
NetCom 123 WLAN Top and Front Side........................................... 118
NetCom 423 WLAN Top and Front Side........................................... 119
NetCom 823RM WLAN Front Side................................................... 120
NetCom 823RM WLAN Rear Side.................................................... 120
1.3. TABLE OF TABLES
Specifications, common........................................................................ 12
Characteristics of NetCom 123 WLAN................................................ 13
Characteristics of NetCom 423 WLAN................................................ 13
Characteristics of NetCom 823RM WLAN ......................................... 13
Characteristics of NetCom 1623RM WLAN ....................................... 13
LED Function ....................................................................................... 15
IP Modem Standard AT-Commands .................................................... 90
IP Modem Extended AT-Commands ................................................... 91
IP Modem S-Registers for Configuration............................................. 91
Master Switch Configuration of NetCom 123, 423, 823RM and
1623RM
Signal Assignment DB9 male............................................................. 116
RS422/485 Jumper Configuration...................................................... 117
823RM WLAN, 1623RM WLAN
...................................................................................... 115
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2. INTRODUCTION
This manual covers several different models of NetCom Devices, in particular the Wireless operating devices. In general the operation is the same on all models, except where explicitly noted otherwise.
The VS NetCom devices are designed to remotely operate serial ports over networks. The new network interface is WLAN (Wireless LAN according to 802.11g) with 54Mbit/s transfer rate. The interface of 100Mbit/s Ethernet as on all cable operated models is also available. The transport is implemented via TCP/IP protocol. Therefore control is available via WLAN, Ethernet, Intranet and Internet. Starting with Firmware version 2.2 all communication with the device may happen encrypted with strong algorithms. The supplied driver software hides the network transfer from your applications. Software applications using standard COM ports need no change to operate via NetCom through the virtual serial ports.
The devices come with a steel case well suited for industrial environments.
NetCom supports high serial speeds up to 3.6 Mbps. All serial ports operate in three configurable ways. There is the common RS-232 mode (up to 921 kbps), and the ports also offer the industrial RS-422 and RS-485 configuration (up to 3.6 Mbps). In RS-485 mode the NetCom may use the Automatic Receive Transmit (ART) control logic to follow the RS-485 specifications for transmitting data. No special code is necessary to be implemented in your software applications.
2.1. FEATURES
Single power supply DC 9V-30V, 200-600 mA@12V
AC 100-240V 47-63Hz, 25VA
Wireless LAN 802.11b/g for 54Mbit/s Ethernet 10/100BaseTx for auto-configuration Three serial port interfaces: RS-232, RS-422 and RS-485 Max. 3.686.400 bps, half- and full-duplex TCP/IP configuration fixed or by DHCP Easy remote configuration via SNMP Drivers for Windows™ and Linux operating systems Documented interface for every networked operating system
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2.2. PRODUCT SPECIFICATIONS
Most of the characteristics are common for all models. However some must differ from model to model.
2.2.1. COMMON CHARACTERISTICS
Processor ARM9 (KS8695P) Memory 16MB SDRAM
2MB Flash WLAN antenna SMA-reverse Ethernet connector RJ45 10BaseT/100BaseTx Serial connector DB9 male (similar to PC) Serial Speed 1 bps up to 3.69 Mbps Parity None, Even, Odd, Mark, Space Data bits 5, 6, 7, 8 Stop bits 1, 2 (1.5) Serial signals
Protocols TCP/IP, UDP, SNMP, DHCP, ICMP, ARP,
Serial operation RS232, RS422/485 configured by DIP switch
Management Serial console, Telnet, Webbrowser, SNMP Driver software Windows 2000/XP, Windows NT, Linux Management software Driver installation and configuration program,
Operating temp. 0° to 55°C Approval CE, FCC
Table 1: Specifications, common
RS-232 TxD, RxD, RTS, CTS,
DTR, DSR, DCD, RI, GND
RS-422,
Tx+/Tx-, Rx+/Rx-, GND
RS-485 4-wire RS-485 2-wire Data+/Data-, GND
Telnet, RTelnet, HTTP
or by software
Management console
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2.2.2. SPECIFIC CHARACTERISTICS
2.2.2.1. NetCom 123 WLAN
Power requirement DC 9V to 30V, 300 mA@12V Dimensions
Weight 250 g
Table 2: Characteristics of NetCom 123 WLAN
2.2.2.2. NetCom 423 WLAN
Power requirement DC 9V to 30V, 400 mA@12V Dimensions
Weight 500 g
Table 3: Characteristics of NetCom 423 WLAN
2.2.2.3. NetCom 823RM WLAN (19” version)
Power requirement AC 100V to 240V, 47-63Hz, 25VA Dimensions 258×149×45 mm³ (W×D×H)
Weight 1350 g
Table 4: Characteristics of NetCom 823RM WLAN
73×115×27 mm³ (W×D×H) 101×121×27 mm³ with connectors
169×93×29 mm³ (W×D×H) 169×99×29 mm³ with connectors
278×155×46 mm³ with connectors
2.2.2.4. NetCom 1623RM WLAN (19” version)
Power requirement AC 100V to 240V, 47-63Hz, 25VA Dimensions
258×149×45 mm³ (W×D×H) 278×155×46 mm³ with connectors
Weight 1450 g
Table 5: Characteristics of NetCom 1623RM WLAN
2.3. PACKING LIST
VS NetCom Power supply adapter,
12V 1 A for NetCom 123 WLAN and NetCom 423 WLAN Power cord for NetCom 823RM WLAN and 1623RM WLAN
CD-ROM with driver and configuration software
Quick Installation Guide
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3. HARDWARE CONFIGURATION
3.1. POWER SUPPLY
The NetCom device is powered by a single 9-30V power supply. It requires 200 mA up to 1500 mA of current, depending on the device type and voltage supplied. A suitable power supply adapter is part of the packaging. Connect the cable to the power jack at the rear side of NetCom, and put the adapter into the socket. For the 19” devices of course just plug the power cord into the socket.
The Power LED on NetCom (red) will light. You can connect a power supply of your choice, providing the technical requirements are met.
3.2. NETWORK
The NetCom may use WLAN or Ethernet at customers choice. By factory settings both interfaces are enabled, and the priority is set for Ethernet (via cable). If no cable is connected here, the Wireless interface is active. Both interfaces use the same MAC Address, to allow for seamless failover from cable to wireless operation.
3.2.1. WLAN A NTENNA
The connector used for the WLAN Antenna is known as SMA-Reverse. This is a standard type to allow for simple connection of different equipment. Just fit the supplied antenna by carefully screwing it to the connector. You are free to connect a cable and a different antenna of your choice, as long as it is designed for WLAN. When the NetCom detects an operational WLAN it can connect to, the Blue LED lights.
3.2.2. WLAN C ONFIGURATION
The pre-defined operation mode is ad-hoc, which means you do not need an Access Point to get access to the NetCom. Any computer with WLAN equipment may contact the NetCom. The configuration of the NetCom is done with the tools described later. This is the most easy way of installation. However the Ad-hoc mode is not encrypted by definition. As a result any station can read the data transferred to the NetCom. This also includes the passwords. Further in case of problems, it is harder to find the source of the problems. Therefore the recommended method is to
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use the Ethernet connector for the first configuration. Or in case of doubt, use the serial port for this.
The configuration of the WLAN parameters should follow in a later step. This is especially the case, if encryption or certain other parameters require certain configuration.
3.2.3. ETHERNET
The connector for Ethernet is the usual RJ45. Simply connect it to your (switching) Hub. When the connect is done the Link LED on NetCom (yellow) will light. When data traffic occurs on the network, this LED will blink. It depends on your network whether a 100Mbit or a 10Mbit connect will be established. A 100Mbit net causes the Speed LED on NetCom (green) to light, otherwise it will remain dark.
Red LED Yellow LED Green LED Status
Off -- -- Device off, no power On Off Off No connection On On Off 10Mbit connection established On Blink Off 10Mbit data transfer (traffic) On On On 100Mbit connection established On Blink On 100Mbit data transfer (traffic)
Table 6: LED Function
3.3. SERIAL PORT SIMPLE SETTINGS
There is one set of 4 Dip switches to configure the operation mode of the NetCom Device. This switch is the Master configuration for each serial port. All ports operate in the same mode, unless the DIP switches configure for software setting. Before connecting a serial device, the serial port configuration must be completed.
Warning: a bad configuration may cause serious damage in the NetCom or the connected device.
To avoid these problems, it is recommended not to connect a device to the serial ports in the first installation. The serial ports should be configured for RS232. This is done by setting the DIP switches like this example.
Image 1: Master Switch Standard Configuration
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4. WINDOWS DRIVER QUICK INSTALLATION
This section describes the minimum steps required to install the Windows Driver and Management programs. Most configuration options are ignored. They are covered in later sections.
Before starting installation, it is essential to have an IP configuration ready for the NetCom Device to install. You may read the section TCP/IP Description below. In many networks the default configuration is fine. If in doubt, please ask your Network Administrator for help.
The following description is based on Windows XP Professional, with Service Pack 2 installed. The installation on other configurations of Windows XP is similar.
Further it is assumed the network access is functional. It is recommended to use Ethernet via Hub or Cross-Over cable.
4.1. INSTALLATION PROCEDURE
The installation of drivers is described first. This is followed by a procedure to verify a correct installation. The last part of this section is the uninstall process.
4.1.1. START THE INSTALLATION WIZARD
This is the Installation Wizard, it is named VSNSETUP.EXE. You’ll find it on the CD-ROM shipped with the NetCom, in the directory responsible for your operating system. The drivers are also
Image 2: Installation Wizard
drivers.
available on the Internet, in the latest version. The Installation Wizard for Windows NT is named VSNSTUNT.EXE. Start this program to install the
Your screen displays a VScom logo. Select the folder to install programs and drivers into. In most situations the suggested setting is fine, just hit enter.
Image 3: Start Driver Installation
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4.1.2. FIND AND CONFIGURE NETCOM DEVICES
Some files are copied to your hard disk, this is the usual process similar to other Windows installations. When all files are copied, the NetCom Manager NetCom Devices on your network.
1
program is started. This searches for all
Image 4: Discover and Select NetCom Devices for Installation
After short time the search process is finished. All discovered NetCom are listed. In your very first installation of NetCom Devices and Drivers you should connect only one NetCom to your network. This single
Image 5: NetCom in Manager
1
This program is covered in detail in a later section. For now follow the minimum
steps.
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Device is listed here. Identify it by comparing the serial number shown in the NetCom Manager.
NetCom 123 WLAN, 423 WLAN,
4.1.2.1. Configure IP Parameters
As mentioned above, it is important to configure the NetCom to operate in your network. In many networks this is done by a special server. Please ask your Network Administrator for information. If you need to define parameters manually, double-click the devices icon.
Image 6: Define NetComs IP Configuration
This panel opens. Deselect the Option of “Use DHCP”, and place your parameters as “IP address”, “Netmask” and “Broadcast”. Click on the “OK” button.
4.1.2.2. Configure Firewall
As you will see in Image 6 the driver may also operate by traversal of a Network Firewall. This requires a special configuration, which is skipped here. Please read in detail in section 5.2.6 Manual Detection/Installation of a NetCom. For now proceed with the standard installation.
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4.1.3. INSTALL DRIVERS
You are now back in the NetCom Manager. Click the “OK” button, the installation continues. Windows detects the serial ports on the fresh NetCom as new Hardware. Since Windows XP Service Pack 2 you are asked about to get latest drivers.
Image 7: Use current drivers dialog
There are no later drivers on the Windows Update website. Select the third item, and click on “Next”. This question neither appears on Windows XP prior to SP2, nor on any previous Windows version.
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Image 8: Install drivers for the serial ports
The pre-selected automatic installation is fine, just click on “Next”. The driver files are already copied to your hard disk. Now Windows installs them in the system directory. To “Finish” the installation click on that button as it appears.
These latest steps happen for each serial port on the NetCom Device. Just repeat the procedure, until all ports are successfully installed. Windows will show you this.
In most situations it is not required to reboot the system. Of course you can do that now, to test the drivers.
4.2. VERIFY THE INSTALLATION
Image 9: VScom drivers in the Start Menu
In the Start Menu you’ll find “Vision Systems GmbH”, a new program group. The installed programs are the NetCom Manager and an option for uninstallation. This group is not installed on Windows NT.
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Image 10: NetCom in Device Manager
In the Device Manager the serial ports are listed in the usual section “Ports”. Additionally there is a new device class “VScom Virtual Com”. All installed NetCom Devices are listed herein. The available options are described later.
On Windows NT there is no Device Manager. You’ll find the serial ports listed in the Control panel in the
Image 11: NetCom Manager NT
“Ports” applet. To configure the NetCom and special port options, there is a new applet named NetCom Manager.
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4.3. UNINSTALL THE DRIVERS
To completely uninstall the NetCom Drivers and files, there are three methods. The usual way is to use the Add/Remove Programs applet in the Control Panel, and remove the NetCom Drivers. This will start the NetCom uninstallation program.
Image 12: Uninstall NetCom Drivers
As a second way you may start the Uninstall program in the start menu. The third method is to start the Installation Wizard again. This will detect the drivers on the system. You have the options to repair the current installation, or to remove the installed drivers.
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5. SOFTWARE CONFIGURATION
The NetCom Devices may also be used without the installation of a driver software. Customer applications contact the NetCom directly, using network functions. These setups require independent configuration of the NetCom Device and the serial ports. There are several ways to do this configuration. The NetCom offers a Webbrowser interface, a Manager program to use in Windows, configuration via serial port, via Telnet and also via SNMP. This SNMP option is not covered in this manual, please see separate documentation. The serial port option is a fallback, if every other way of configuration fails. The options are here described in the order Web, Manager program, Telnet and serial port.
Configurations via Webbrowser and via Telnet require a functional TCP/IP connection to the NetCom Device.
Image 13: NetCom Manager
is a very minimal description of this program. You find this program on the CD-ROM shipped with the NetCom Device. In Windows 2000, XP and 2003 it is named NETCOMMGR.EXE, while in Windows NT the name is NETCOMMGRNT.EXE. Just double-click to start it direct from the CD-ROM. If you already installed the drivers, the program is also in the Start Menu.
And you must also know the IP-Address of the NetCom, to contact it. The easiest way to retrieve this information is the NetCom Manager program. So here
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Image 14: NetCom Manager Servers Panel
Identify the NetCom Device by comparing the serial number. Double-click the Icon of the NetCom. You’ll see the IP-Parameters. Note the “IP address”, to use it in your browser or via Telnet.
Image 15: NetCom IP-Parameters
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5.1. CONFIGURE IN WEB-INTERFACE
Open your Webbrowser. In the address line type the address of the NetCom Server. In the example from above type http://192.168.254.254 as the target. You may do this on any operating system you prefer.
Image 16: Webinterface for configuration
The NetCom welcomes you with its “Home” screen. To access the different options of configuration, the images above function as a link. In many menus you’ll see a blue question mark. This is a symbol for help. When clicked a short explanation pops up, informing about the function of this parameter. Some other settings require a reboot to save and activate them. Whenever this situation occurs, the NetCom requests a REBOOT.
It is done like this here, you may reboot now, or do that later when the configuration is finished.
Image 17: Webinterface Request to Reboot
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5.1.1. WEBBROWSER SERVER CONFIGURATION
The Server Configuration is a very long menu. It is divided in its logical sections throughout this document. There is basic server information, the server parameters related to the IP-configuration, the parameters for Wireless communication, the section for encrypted communication, Password settings, and finally the configuration for date and time.
5.1.1.1. Server Info
Information about the selected NetCom is displayed as “Server Info”. Starting with the “Server Type”, this is the model of the NetCom, followed by the version of Software and Hardware. This will give a rough overview, which features are implemented,
Image 18: Web Panel Server Information
important to identify the device you are configuring right now. For further information the “UpTime” is listed. “Contact” and “Location” are User-defined information. They may later help to find the device in the installation, and the person responsible for management.
or need an upgrade of the firmware. The “Serial Nr.” is
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5.1.1.2. Server Parameter
The “Server Parameter” allow configuration of the NetComs name and of course all parameters in IP-settings. The Server Name is used as the ESSID of the Wireless Ad-hoc mode. Generally it is used as information, e.g. in the NetCom Manager program or in SNMP. You may choose the network interface as
Wireless
or both (with
Cable,
priority). Manual changes of IP parameters
are only available with “DHCP” set as
Disabled. When DHCP
is not used, enter “IP Address” and “Netmask”, as well as the
Image 19: Web Panel Server Parameter
“Broadcast” address. “Gateway”
is required, if there are Routers in the network. DNS is used to access other stations by name. The “ConfigPort” is used to access the NetCom for administration via Telnet. It is suggested to use the standard value for Telnet, TCP port number 23. However it may be changed for different purposes. This does not change the function of the Telnet menus.
Firmware version 2.2 introduces the new function as Print Server. The TCP Port defined by RFC1194 is 515, under certain circumstances you may change the “PrintServerPort”. More about Print Server function at the configuration of the serial ports.
“KeepAlive” is an intrinsic function of the TCP/IP protocol. If used it causes network traffic, but problems are detected earlier. In a LAN this is usually not a problem. However, if used via DialUp connections this may cause problems. If this functions is used, you must define an interval in seconds. NetCom has a better chance to react on network problems, or failed hosts. Even dropping an old connection may be useful in certain environments.
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5.1.1.3. Wireless Parameter
To operate a Wireless device, a lot of parameters are required. The configuration in the NetCom is reduced to a small set of them, for ease of configuration.
“SSID” is the «Service Set Identifier». This is used to get access to radio cells established by an Access Point. By default it is built from the serial number, as identification in Ad-hoc mode.
The “OperationMode” is
Image 20: Web Panel Wireless Parameter
selectable as a direct connection from
Ad-hoc for
wireless stations to other
stations, and also as
infra to select the «Infrastructure Mode». This
mode is required to connect to an Access Point. Other wireless stations such as a PC or Laptop use the Access Point to transfer the data to the NetCom.
The “WirelessMode” is available as
11b and 11b+g. It may be
necessary to use the restriction of 11b when compatibility problems with other clients occur.
WLAN as of IEEE 802.11b/g define eleven possible channels (i.e. predefined frequencies) to use with WLAN devices. The available “CountryRegion” values are
FCC(1-11) for North America.
In Infrastructure Mode the NetCom adapts to the configuration of the Access Point.
The “Channel” is used in Ad-hoc mode.
“Encryption Type” defines the encryption of the radio transmission. It may be
Off, WEP or WPA-PSK/TKIP. The WEP encryption may use 40
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or 104 bit keys, sometimes also named WEP40/WEP64 or WEP104/WEP128. Which of this is required is defined by the “Encryption Key” Parameter. The key may be entered as ASCII characters, or as hexadecimal for a binary key. A string with 5 characters is WEP40 using an ASCII key. Using 10 characters as key defines this key as also WEP40, but with a binary key in hexadecimal notation. Likewise a 13 character string is WEP104 with ASCII, and 26 characters select WEP104 with a binary key. WPA Encryption is available for the TKIP protocol. The key is PSK (Pre-Shared Key) and must be installed on all stations. It is recommended to use WPA-PSK/TKIP with a binary key, generated from random data.
“RTSThreshold” and “Fragmentation Threshold” are low level WLAN parameters. They should match the configuration in the Access Point. Higher values result in better data throughput. But when transmission error occur, the impact is dramatic. In this case lower values provide better security and better performance.
5.1.1.4. Encrypted Communication
Firmware version 2.2 introduces a way for encrypted communication with the NetCom Serial Device Server. This function establishes an encrypted VPN tunnel between your computer and the NetCom. All communication to the NetCom uses this new connection. No application requires a change of operation, but seamlessly gets the advantages of Encryption.
To build this tunnel NetCom uses the Open Source product OpenVPN™ (http://openvpn.net
). This is the configuration of the parameters on the NetCom side. The function and the configuration of OpenVPN™ is described with more details later in the section of OpenVPN™ Client installation.
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Of course “OpenVPN” may be
Disabled, active as Server or
in the combined Server- Client mode. When the function is active, the NetCom is virtually invisible on the IP-Address defined in Server Parameter. It will still answer on ICMP, and also the Logging function is available. There is only one connection accepted by the NetCom, to the “TCP Port” defined for OpenVPN™. There is nothing more available.
The “IP Address” is the local
Image 21: Web Panel OpenVPN Network Parameter
address on the VPN, it should be a
private address. This VPN also has a “Netmask” and a “Broadcast” address, this is similar to the configuration of the “Server Parameter”. The Limit of “Max. Clients” specifies how many stations may establish simultaneous connections to the NetCom; it does not limit the number of installed clients. If OpenVPN is configured for Server-Client mode, it will establish a connection to a given Server, e.g. another NetCom. The “TCP Port” and the “IP Address” of the Destination are required.
Different grades of “Encryption” are available, from no encryption at all to AES with a 256 bit key. Select the required grade of security, and open the “Configuration-Settings of the Encryption-Key” to open a window for the parameters.
Image 22: Web Panel OpenVPN Encryption grades
Image 23: Web Panel OpenVPN Key Configuration
This window is for Key management. The NetCom allows to “Generate” a new key from Random Data. This key is the displayed in the browser window. Depending on the configuration of your
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Webbrowser, it will attempt to immediately save the key to a file on your disc. Since the Internet Explorer also shows this behaviour, the Firmware suggests a file extension of “.cfg” instead of “.key”. Windows may react crazy on “key”-files. Please also note, this fresh new key is only displayed/saved. The configuration of the NetCom has not changed.
To use this new key on the NetCom, you must “Load” it to the NetCom. This is the way to “Upload” any key to the NetCom, regardless of the source. Instead of loading a new key to the NetCom, it is possible to “Show” the key currently used. Again some browsers including Internet Explorer directly attempt to save the key.
If “Logging” is enabled, NetCom sends the messages of OpenVPN™ to the standard debug log output.
5.1.1.5. Authentification
”Authentification” sets a password to restrict access to the configuration of NetCom. To protect against accidental
Image 24: Web Panel Authentification
mistyping, you must type the Password twice.
5.1.1.6. Date & Time
It may be helpful to have a correct time setting in the NetCom. You may manually enter the time here. Please note, there is no real time clock with a battery backup in the NetCom. When the NetCom is restarted, the time is lost.
But since Firmware version 1.6 it is possible to configure NetCom for automatic time retrieval via SNTP. Define “State” for retrieval method of “Interval” or “Startup”, or “Off”
Image 25: Web Panel Date & Time
of course. Parameter “Mode” is
used to find the Time Server. It may be defined direct, or by DHCP. The “Interval” in seconds instructs the NetCom to regularly check for an update of the internal time settings. The Time Server may be given by IP-Address, or by name. A
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name of course requires a DNS server, see at 5.1.1.2 Server Parameter above.
Below these options there is the button “Save”. This will store all configurations done here in the NetCom. In many cases NetCom requires a reboot to proceed.
5.1.2. WEBBROWSER SERIAL PORT CONFIGURATION
This is also a huge menu. Each serial port of the NetCom is listed in a separate Column. The top half of the parameters titled “Serial Settings” is directly related to common serial configurations. The bottom half titled “Transfer Settings” configures the operation mode of NetCom on the network. Each serial port is configured separately, there is no setting shared between ports.
5.1.2.1. Serial Settings
The NetCom devices allow to operate in RS422/485 modes. This is configured by the Master DIP switches or by software, “PortType (current)” displays the current setting. If the DIP switches are set for «
Selected by Software», the mode
of operation is chosen by the “PortType” parameter.
Image 27: Web Panel Op-Mode by Software
The serial port is based on enhanced
Image 26: Web Panel Serial Settings
UARTs, the type and maximum speed are also displayed.
When the NetCom is used via the Virtual Com Driver mode, the serial parameters are controlled by the application, which opened the serial port. However certain installations use a different operation without Driver mode. Then the serial parameters must be defined separately. This is done in this panel.
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The current UART “Model” may be virtually changed to a less advanced type. In some situations it may be desirable to deactivate the FIFO memory, or some other options.
The “Baudrate” may be selected in a drop-down list, or entered manually. If
Manual is selected in the list, the value in the respective
field is used to transmit data. NetCom checks if the configuration is possible, and warns otherwise. Note: The “MaxBaudrate” shown is kind of safe settings. It is achievable in RS232-Mode with proper cabling. However, the NetCom may operate in RS422 or RS485 configuration. These are much less sensitive for noise. It is possible to configure a bitrate of four times the MaxBaudrate, usually 1.843.200 bps.
“DataBit” per character, “Parity” and “StopBit” are quite usual parameters.
The FlowType is available as standard configuration. There is also an Advanced setting, which gives very specific control to the user.
NetCom can generate Events on RTS, DTR or as XON/XOFF, when the serial receive buffer is filled/emptied. It will also respect the state of CTS, DSR or XON/XOFF when sending data to the connected serial device.
Image 28: Web Panel Advanced Flow Control
The “RxTriggerLevel” defines when NetCom sends the received data to the host. If the amount of data is this high, the data is sent. It does not matter if there is still data coming on the serial line. If less data is received, the NetCom waits some time for further data, before sending the buffer.
The “TxTriggerLevel” operates similar for the transmission. If the defined amount is received from the network, the NetCom does not accept more data to transmit.
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5.1.2.2. Transfer Settings
The Transfer Settings allow different
Image 29: Web Panel Serial Port Mode Selection
modes. They are selected by the basic “Mode” setting. Depending on the
current mode, only some of the many parameters are useful. The web configuration hides those parameters without function. Basically the NetCom Devices can act as a server or as a client. As the main difference a server waits for clients to contact it, while a client actively contacts a server. A NetCom can do both, and partially both at the same time. Keep this in mind throughout this section.
5.1.2.2.1. Driver Mode
Only very few parameters have a
function in “Driver Mode”. NetCom is
operating as a Server. It accepts two
connections per serial port. One
connection is used to transmit the
serial data, this is the
Image 30: Web Panel Driver Mode
“TCP Port(Data)”. And the other is used to transmit control information, “TCP Port(Control)”. This control connection includes the configuration of the serial port, as well as signals for changed Modem Status lines. This mode is required when the serial port is operated via the Virtual Com Driver, it is default.
The NetCom can check if the connected Client is still alive. This may be done, when a second Client wants to establish a connection (
On Connect). It may also be done in regular intervals (Polling).
5.1.2.2.2. TCP Raw Server
As TCP Raw Server NetCom operates very simple. It only waits for incoming data connections in Raw IP mode. As with the Driver Mode only the data connection is defined. As a special configuration NetCom allows for more than one connection at a time. If the number is raised, it is the responsibility
Image 31: Web Panel TCP Raw Server
of the customer to ensure correct operation. Firmware version 2.2 added
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the option of additional protection by “Password”. When a password is configured, the NetCom sends the question “Password: “ to the client. The user (his application) must first send the password, followed by a <CR> character. The password is not echoed to allow usage with Telnet on a Monitor.
5.1.2.2.3. TCP Raw Client
Also as Raw Client the NetCom requires very few parameters. Under certain conditions it establishes a Raw TCP connection to a pre-defined “Destination”. Since version 2.0 of the NetCom
Image 32: Web Panel Raw Client
Firmware the Destination can hold multiple hosts as targets for a connection. They are entered as a comma separated list of DNS names or IP-Addresses. Each destination will have a TCP port number, separated by a colon. Instead of a single IP-Address or DNS name, a range of IP-Addresses is also valid. This range must be followed by the TCP port number, as in 192.168.254.12-
192.168.254.17:2077. The parameter “Connect” defines if NetCom uses the connections as
Permanent, Triggered or DSR. With Permanent or Triggered
any activity on the serial ports establishes the connection, inactivity of longer than the “ShortHoldTime” cause NetCom to close the connection.
DSR is new since Firmware version 2.0, the
TCP-connections follow the state of the DSR signal at the NetCom serial port. When it becomes active they are established, until DSR becomes inactive. At that moment the connections are dropped.
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5.1.2.2.4. Null Modem Tunnel
This is a mixed mode, requiring parameters for server function and for the destination. The NetCom operates as a server while accepting connections in Driver Mode. If there is no current connection, the NetCom may establish a connection as a client. This is also a special connection, using the Driver Mode protocol. NetCom can will not only transmit serial
Image 33: Web Panel Null Modem Tunnel
data in both directions, it will
also pass information about the current settings of the Modem Status lines. And it will itself set the Modem Control lines as required by the other host. Since this operation requires another NetCom to accept the connection, both NetCom together operate as a long Null-Modem cable. The data is sent via a tunnel through the network.
The configuration as Server (top) requires the same parameters as the Driver Mode, hence “TCP Port(Control)” and “TCP Port(Data)”.
The configuration as Client (bottom) first require a destination. Here it is given by name, but a direct IP-Address may be more usual. On the destination there is also a “TCP Port(Control)” and “TCP Port(Data)” to accept the connect of the NetCom.
The connection is normally established in
Triggered mode, i.e. when
some event occurs on the serial port. It is hold for the defined “ShortHoldTime”. It is also possible to have the connection
Permanent. As in the normal Driver Mode the function of a connected
client can be checked via KeepAlive signals in different modes.
5.1.2.2.5. IP-Modem
The serial port of a NetCom may
mimic (emulate) a serial modem.
This feature is available since
Firmware version 2.0 of the
NetCom. There is the separate
Image 34: Web Panel IP-Modem
section 8 below defining this
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functionality. Here are the basic network parameters only. A modem accepts connections from the network, in this case via TCP/IP. The TCP port for this is defined as the “TCP Port(Data)”. This is the only parameter required to set here. All other values are normally defined via AT-commands. However for short, “Destination” allows for up to four predefined targets, available with special Dial commands. The “IP Modem Config” is known as the Init String in standard modems.
5.1.2.2.6. TCP Advanced Settings
All of the above operation modes are special configurations for options. In some situations none of the pre-defined modes fit the customers needs. When this is the case, the TCP Advanced Settings offer the configuration of any Transfer parameter. Unusual combinations of Modes are possible with this, also standard modes with unusual parameters.
Image 35: Web Panel TCP Advanced Settings
5.1.2.2.7. UDP Data Transfer
The UDP mode is available as a function since the version 1.4 of the firmware. UDP sends data in single packets instead of a stream. This protocol requires a “UDP Port(local)” for listening to incoming data. Other stations on the network
Image 36: Web Panel UDP Data Transfer
send their data to this port. The “Destination” host is
configured by IP-Address or name, plus the target “UDP Port(Dest)”. “UDP MaxPacketSize” is a limit for the size of UDP packets. When the
amount of data received on the serial port reaches this limit, the UDP Frame is assembled and sent to the destination.
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“UDP Timeout” defines when NetCom sends the received data as a UDP Frame. If the reception of serial data is interrupted for this time (in milliseconds), the data sampled so far is sent to the destination. “UDP Trigger” defines a sequence of characters. As soon as this sequence is detected in the received data, all data up to the end of this Trigger is sent to the destination. In most situations such a Trigger includes control or other special characters. Enter them numeric: as \xHH where HH is the hexadecadic code of the character, or as \OOO where OOO is the octal code of the character. The backslash itself must be doubled as \\.
5.1.2.2.8. Print Server Function
Firmware Version 2.2 introduces the function as a Print Server according to RFC1179, also called a »Line printer daemon«. A print server is accessed through its IP Address via one specified TCP Port (see Server Parameter). Data is handled in distinct queues, each with a certain name. Each queue is handled by a certain serial port, and the data is sent to the serial printer attached to this port.
Each serial port configured for Print Server operation has its separate “QueueName”. The default value is »lpd« plus port
Image 37: Web Panel Print Server Configuration
number. The “InitString” is a
special feature of NetCom. This string is sent to the serial printer at the beginning of the next queued print job. The definition is in section 8.2.2.1 below.
5.1.3. WEBBROWSER NETCOM TOOLS
Since Firmware version 1.6.0 the available tools are:
The Ping utility to check if a station is available.
Statistic information for each serial port.
The Netstat utility to monitor used TCP connections.
The option to detect WLAN devices in the proximity
The option to update the firmware.
Saving of Configuration to / Loading from a file.
Syslog
DebugLog
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5.1.3.1. Ping
Enter the IP-Address or the name of a station in the field, and click the “Ping” button. The network connection is checked by sending
Image 38: Web Panel Ping
certain ICMP data packages.
PING 127.0.0.1 from 192.168.1.87 : 44 (72) bytes of data 52 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=1.560 msec 52 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=1.542 msec 52 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=1.542 msec
back
If the target responds, the network between the NetCom and the target is operational. The time required for an echo depends on the speed of the network. In a typical Ethernet this is only very few Milliseconds, while it can be several seconds throughout the Internet.
5.1.3.2. Statistics
Select the serial port to see its statistical information.
Image 39: Web Panel Statistics Port Selection
The statistics window reports the state of the modem status and control signals. Also the number of state changes. The number of characters sent and received is shown at the bottom.
Image 40: Web Panel Port Statistics
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5.1.3.3. Netstat
Use Netstat to see the actual connection status of NetCom. This is a standard tool for
Image 41: Web Panel Start Netstat
network debugging.
Update
Proto Local Address Foreign Address State tcp 0.0.0.0:23 0.0.0.0:0 LISTEN tcp 0.0.0.0:80 0.0.0.0:0 LISTEN tcp 0.0.0.0:2000 0.0.0.0:0 LISTEN tcp 0.0.0.0:2001 0.0.0.0:0 LISTEN tcp 0.0.0.0:2010 0.0.0.0:0 LISTEN tcp 0.0.0.0:2011 0.0.0.0:0 LISTEN tcp 0.0.0.0:2020 0.0.0.0:0 LISTEN tcp 0.0.0.0:2021 0.0.0.0:0 LISTEN tcp 0.0.0.0:2030 0.0.0.0:0 LISTEN tcp 0.0.0.0:2031 0.0.0.0:0 LISTEN tcp 192.168.1.243:80 192.168.1.42:1280 TIMEWAIT tcp 192.168.1.243:80 192.168.1.42:1281 ESTABLISHED udp 0.0.0.0:161 udp 0.0.0.0:19970 udp 192.168.1.243:32331
Image 42: Web Panel Netstat Output
A “Foreign Address” of 0.0.0.0 is listed when NetCom is waiting for an incoming connection ( connection is either active (
LISTEN). If the value is not 0.0.0.0, the
ESTABLISHED) or closed (TIMEWAIT).
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5.1.3.4. Wireless
When it comes to Wireless communications, it is useful to see a list of possible partner stations on the WLAN. This function is available in many drivers, and also in the NetCom WLAN Serial Device Servers.
This function is often referred to as »Range Scan«. On the NetCom it will open a
Image 43: Web Panel WLAN Scan
separate browser window with the results. An example of this is shown below.
Wireless-Devices in Range
Update
Act MAC SSID Channel Mode Enc
X 86:73:F6:22:E1:BA NetCom_0210100462 7 Ad-Hoc X A6:E8:9E:BE:7D:86 NetCom_0210100444 7 Ad-Hoc X 00:0F:B5:66:CF:56 NETGEAR 11 Managed X
Current Rate: 11Mb/s
Image 44: Web Panel WLAN Scan Output
This example lists two other NetCom configured for Ad-Hoc communication on channel 7. Both use no encryption. There is also an Access Point (listed as Managed), of course in Infrastructure-mode. To connect to this AP the NetCom must use encryption.
Since the NetCom itself is in Ad-Hoc mode, the communication is limited to the 802.11b, which results in 11Mb/s as raw transmission speed.
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5.1.3.5. Firmware
To upload a new version of the firmware, put the name of the file in the
field. Your Webbrowser may allow to search for the file. Click on the “Update” button. While loading the file is checked. If it is valid, it is stored in the Flash Memory. When the upload is finished, NetCom will
Image 45: Web Panel Firmware Upload
Reboot.
5.1.3.6. Save and Load
Configuration
Image 46: Web Panel Save/Load Configuration
It is possible to save the actual configuration to a text file. This is first implemented in Firmware version 1.6. Of course it is also possible to load the saved configuration into a NetCom.
5.1.3.7. Logging and Debug
Syslogging requires a server the information is sent to. Facility allows to select the data sent to that server.
For Debuglog the NetCom behaves as the server. Open a TCP connection to the configured port, and receive all information generated.
Image 47: Web Panel Syslog & Debug
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5.2. CONFIGURE WITH MANAGER PROGRAM
Shipped with the NetCom Devices there is a versatile program for Windows Operating System, named NetCom Manager. This program shall detect, manage and configure the NetCom Devices in your network. You can start it by several ways. First of all it is stored on the CD-ROM, named NETCOMMGR.EXE (NETCOMMGRNT.EXE on Windows NT). It is possible to start it directly from the CD-ROM.
See this Icon to the left. When the Virtual Com Drivers are installed, there are more options to run the program.
Image 48: NetCom Manager
In Windows 2000, XP and 2003 Server the driver software installs a new device class “VScom Virtual Com”. The properties of the class open the NetCom Manager. Additionally the installation of the drivers created a new program group in the Start Menu.
In Windows NT the same Icon appears in the Control Panel, to start the NetCom Manager program.
Image 49: NetCom Manager in Start Menu
Image 50: NetCom Manager in Device Manager
This section of documentation focuses on management of the NetCom Devices. The options to configure driver-specific options of the serial ports are skipped here. This includes some buttons and panels. They are described in total below, in the documentation of the drivers and panels.
While in the configuration process, a click on a button or a double-click on an item opens properties or other options. In many situations, a right-click with the mouse opens context-sensitive options. Just try it out. The NetCom Manager is designed to help configure driver options. So for very detailed configuration of a NetCom, it is better to use the Webbrowser interface, or do it via Telnet. However, here are the options.
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5.2.1. STARTING NETCOM MANAGER
When NetCom Manager is started, it will “Search” the NetCom in your LAN by SNMP. This process may take up to 30 seconds. The devices in a LAN are typically found in the first seconds. If this is enough for you, you can stop the search by click on the “Done” button.
Image 51: NetCom Manager “Servers” Panel
The NetCom are listed here in the “Servers” panel. Since the “Search” uses broadcast mechanisms, the range is limited. If you have routers in your network, or you contact some NetCom via Internet, you must “Add” them manually. Enter the network parameters to access the NetCom.
Select a NetCom, and click on the “Properties” button, double-click the Icon, or use a right click. Using “Verify” the NetCom Manager contacts the NetCom to check if it is properly configured and online. “Exclude” is only useful in conjunction with the Virtual Com Drivers, so skipped here. “Search” repeats the search from the program start, and may be used at any time. “Remove” removes a server from this list. This option is most often used to clear old data from the drivers database. For monitoring purposes you may select a NetCom, and “Start Log” for
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this. It may be done for several Devices at the same time. The output is visible in the “Log Windows” panel.
Image 52: NetCom Manager Server Settings
5.2.2. NETCOM SERVER SETTINGS - INFO
As described above, open the “Properties” of a NetCom Device. The Server Settings start with the “Info” panel. Configure the options as your network requires.
The “Server Name” is just for information. As factory setting it includes the serial number of the device. You may change it to any string, since there is no functionality related to the name. This name is listed in the Server panel of NetCom Manager. The next parameters are fixed, and displayed for information only.
The “Telnet port” allows to configure this NetCom via Telnet. The value is a TCP port. Factory setting is the standard port for Telnet, 23.
By default the NetCom is set to “Use DHCP” for automatic configuration of IP parameters. This is the suggested method. However there are several situations where this option can not be used. In this case deactivate it. When inactive, other parameters may be changed.
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The basic parameters “IP address” and “Netmask” are mandatory. If any of these is changed, the NetCom Manager calculates a matching address for “Broadcast”. You may also change this address.
The DHCP option will also configure the “Default gateway” and the “Name server”. Without DHCP you must enter these parameters by yourself. However they are not required in all configurations. So enter
0.0.0.0 if they are not used.
5.2.3. NETCOM SERVER SETTINGS - PORTS
Image 53: NetCom Manager Ports Panel
The “Ports” panel lists all serial ports of a NetCom. Some of the options are driver related, e.g. the “Com Number”. Each serial port may operate via three TCP ports. The “TCP Control Port” is used in the Virtual Com Driver mode, and also in Null-Modem Tunnel. If Driver mode is not desired, this parameter is ignored almost always.
The “TCP Data Port” is used to transmit data to and from the serial port. Use the default, or change the value to the settings required for your network. There is also a “UDP Data Port”, used in packet data transfer. You can not switch the NetCom to UDP mode with the Manager. But if it is already in this mode, you can change this basic parameter.
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5.2.4. NETCOM SERVER SETTINGS - FIREWALL
Image 54: NetCom Manager Firewall Panel
Many networks use a Firewall to protect the stations in the network from other networks, including the Internet. In some situations the contact to a NetCom must pass through such a Firewall. To do this you must “Enable Firewall”, and enter the “Address” of the Firewall.
The Manager configures a NetCom via SNMP, which uses UDP. The Firewall must have a special “Port” to receive those data, and to transfer it to the internal network. Enter this port here.
The same scheme applies to the logging option. By default a NetCom listens on port 1200 for logging connections. The Firewall must also have a special “Log Port” to receive this connection, and to transfer it to the NetCom.
The NetCom does not need any configuration to operate in a Firewall protected environment. This configuration here is for installation of the drivers. There is a Firewall tutorial section later in this manual.
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5.2.5. NETCOM SERVER SETTINGS – OPTIONS
Image 55: NetCom Manager Options Panel
This Panel is available since software version 1.4.8.0, in this enhanced version. A “Safe to File” of the configuration is available, as well as the opposing “Load from File” of this data.
You can also “Reboot” the NetCom. This may be useful, e.g. if an old connection blocks access to the NetCom.
The button “Apply Changes” commits all parameter settings done so far to the NetCom. And the “Verify” checks the current settings by reloading the status from the NetCom to the Manager program.
When you want to install a “Firmware Update”, use this button. The NetCom may be protected for access, in this case you must place
the current “Server Password” in the dialog. The option to change the password is reserved for a future extension. “Exclude Server” is related to the Driver installation only.
You may “Enable Log” to see events at the NetCom, for monitoring. If enabled, the log will also appear in the central “Log Window”. At any time it’s possible to “Clear” the log, or “Capture” the data to a file.
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5.2.6. MANUAL DETECTION/INSTALLATION OF A NETCOM
Sometimes the NetCom Device Server can not be detected by the automatic in the NetCom Manager. To detect and configure devices the protocol SNMP is used. The detection is done by sending out a broadcast on all available network interfaces of your computer. This SNMP broadcast is realized as an Ethernet broadcast. Such a broadcast is only transmitted through Hubs and Switches. When there is a router between the computer and the NetCom, the broadcast is not transmitted. This is especially the case when the NetCom is located somewhere via Internet, but also in big networks of some companies. If this is the case, the detection has to be done manually. Refer to Image 51 and “Add” the NetCom by use of the button. Enter the IP-Address of the NetCom in the NetCom Manager Server Settings, and click the button “Verify”. Since now the IP-Address of the NetCom is known, the NetCom Manager sends a request directly to this target. This directed SNMP request is transported, even by routers. The NetCom sends the normal reply, giving all required information to the NetCom Manager. Now it is possible to configure all options as usual. Also the drivers for virtual serial ports are installable now.
Please note, the drivers require to have the IP Address. They can not operate using a DNS name, because a driver can not perform a DNS name resolution. If your NetCom is located on a dynamic IP Address (e.g. on a DialUp connection with 24 hours disconnection), you need to reconfigure the driver installation, when the IP Address has changed.
5.2.7. FIREWALL TRAVERSAL CONFIGURATION
There are more difficult situations with a Firewall between the NetCom and the NetCom Manager. Many Firewalls protect the internal LAN by using the feature of NAT (Network Address Translation). In this situation the IP-Address of the internal device is not visible on the Internet. Only the Firewall can be contacted via its public IP-Address. The NetCom Manager and the driver software for the virtual serial ports can handle such setups. But this requires certain configurations.
5.2.7.1. SOHO Firewall example
The most easy situation for such a setup is by using a very simple SOHO router as the Firewall. This configuration will show the principle of the technical details. Those principles can be transferred very easy to the configuration of more complicated installations. On the SOHO
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router there is only one public IP-Address on the external side, and typically 254 internal IP-Addresses for the LAN side. These internal addresses may be assigned by DHCP or static. Such routers offer a feature typically named “DMZ”, which in fact is only a single exposed host. It is recommended not to use the “DMZ” for several reasons, some of them are security related.
5.2.7.2. SOHO Virtual Servers
The router also offers “Virtual Servers”, which is the option required for NetCom installation. These “Virtual Servers” (here named VSrv for short) operate by a technique called PAT (Port Address Translation). Certain data addressed to the public IP-Address of the router are forwarded to the internal private address of the NetCom. The NetCom can be contacted via the public IP-Address of the router.
First you need to configure the router for some VSrvs. As the absolute minimum there is one VSrv for the NetCom device itself, and another two VSrvs for each serial port of the NetCom. Those VSrv are to be configured for TCP or UDP transmissions. Please read in the manual of your router how to do that. You need a port for the external interface, and an IP-Address plus a port for the LAN side. The IP-Address is of course that of the NetCom. As an example the most easy device is a NetCom 113. The internal port for SNMP is 161 for UDP. The serial port requires ports 2000 and 2001 for TCP.
Function External port Internal port SNMP 8161/UDP 161/UDP Control 9000/TCP 2000/TCP Data 9001/TCP 2001/TCP
Configure your router for these example VSrvs, and use the internal IP-Address of the NetCom for the targets. Connect the NetCom to your LAN. Now you are ready for a very first test. Use Telnet to connect to the Data port of the NetCom serial port. Open a console (DOS Box) and type the command
Telnet <routers-IP-Address> 9001 You will be connected to the serial port. Every character you type is sent out of the serial port, and every received data is shown on your screen. The serial parameters are preconfigured in your NetCom.
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5.2.7.3. NetCom Detection through SOHO Firewall
Now open the NetCom Manager as in section 5.2.6 above, and click the “Add” button. You again get the NetCom Manager Server Settings dialog. But now you have to select the panel named “Firewall”.
Image 56: NetCom Manager Firewall Panel
Check the Option “Enable Firewall”, and enter the IP-Address of the router in the “Address” field. In the field “Port” enter the target port for the SNMP configuration. From the Virtual Server example above this is port 8161. Since there is no configured VSrv for Logging, ignore this field. Click the button “Verify” to have the NetCom Manager contact the router. This is a directed request, so there is no problem with broadcasts. Some ISP will block the SNMP protocol, which typically means they do not transport data for 161/udp to their customers (this is the first reason why port 8161 was used in the example). The router will transfer the request to UDP-Port 161 on the NetCom, which is the port for SNMP. The NetCom will answer the request, and send it out to your computer. The NAT function in the router will exchange the source IP of the data by its own public value, so the NetCom Manager will see the
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answer come from the router. The NetCom Manager is satisfied with this data.
This answer brings every required information about the NetCom, including its internal IP-Address. Select the panel of NetCom Manager Server Settings to verify the information, but do not make any changes here.
5.2.7.4. Serial Ports through SOHO Firewall
Now the NetCom is available in the NetCom Manager, but still the serial ports are not usable. The information of the TCP-ports for the VSrv related to the serial port is still missing. In the NetCom Manager Server Settings select the NetCom Manager Ports Panel. In this panel select one serial port, in this example of NetCom 113 there is only one serial port. Click the “Properties” button to open the configuration of the port.
Image 57: NetCom Manager Port Configuration for Driver
Since the Firewall function is enabled, the parameters for “Firewall mapping” are available for editing. Enter the ports defined in the router,
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9001 and 9000 in this example. Please note, so far there is no number for the Virtual Com Port available. The driver is not installed in this moment, and Windows does not know about the available hardware. This will happen later in the installation. Click the “OK” button, and proceed with the driver installation as already described.
5.2.7.5. DMZ and Virtual Servers
Why is it recommended not to use the DMZ function of the router? There are two reasons. The first one is simple, only one device in the LAN can be defined as the DMZ target. The DMZ is implemented as “Send all IP data targeted for the router to the DMZ station, as long as there is no specific rule for a different target”. When a second NetCom shall be installed on the LAN, the Virtual Servers have to be configured anyway. The second reason is the security. Using the DMZ the Firewall in the router becomes transparent. All data from outside is transferred to the LAN, including all malicious data.
5.2.8. DYNAMIC IP ADDRESS AND OPENVPN™
Since Firmware version 2.2 there is a different method to provide a tunnel to the NetCom. The option of Encryption uses a Virtual Private Network (VPN) based on a single TCP connection between the NetCom and a client computer. Regardless of strong encryption or even weak as not encrypted, here the key point is the single TCP connection. It is more simple to provide a Firewall configuration for a single connection, so the Router Firewall is more easy to set up.
The network link established by OpenVPN™ requires to have a target address and a port number. Since the basic TCP connection is activated by the openvpn.exe program, there is the freedom of using a DNS name for the target device.
With a Dynamic IP Address for the NetCom site, one of the several Internet services for Dynamic DNS (DDNS) may help. It is even relatively simple to construct an own version. Using this service the openvpn.exe program gets the IP Address of the Firewall Router, and will establish the link. When the IP Address changes (after 24 hours), the connection first gets lost. OpenVPN™ will continuously attempt to connect again. When the new IP Address is known via DDNS, the network link is re-established. The NetCom is available again. Even when a serial port has been open, the function will continue seamlessly.
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5.3. CONFIGURE NETCOM VIA TELNET CONSOLE
There are many situations, when using the NetCom Manager program for Windows is not appropriate. And a graphical Webbrowser may also be unavailable. To enable configuration also in this situation, there is the Telnet option. It is preferred by many users.
To connect your Telnet session you need the IP-address of NetCom. Also you must be able to communicate with NetCom via IP. If you can send a PING to NetCom and receive an Echo, the configuration is fine. This requires a predefined NetCom, maybe via a DHCP server. You may also use the NetCom Manager Program (on a different computer) to find the IP-Address of the NetCom. Start your Telnet program, set it to use a terminal emulation of VT100. This is recommended, but VT52 is also possible. The Telnet session is closed by the NetCom, when no user input occurred for at least 3 minutes.
In your Telnet, establish a connection to the NetCom. If the configuration port is changed from the default 23 for Telnet, use this port. If the NetCom is password protected, you need to enter the password right now.
Please enter your password:
Image 58: Telnet Password protected option
When connected to NetCom you must define the type of terminal used.
Please choose your terminal type (1:VT100 2:VT52 [1]): 1
Image 59: Telnet Open configuration menu
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5.3.1. TELNET MAIN MENU
The configuration with Telnet is menu-driven.
+------------------------ NetCom - 123 WLAN V2.0.0 ----------------------------+ | ServerConfig SerialPorts Tools Save&Exit | +------------------------------------------------------------------------------+
+--------------------------------------------------------------------- h=HELP -+ Server configuration settings
Image 60: Telnet Main menu configuration console
This is the start point for configuration. “ServerConfig” has all options to configure the NetCom device itself, including the IP-Parameters to access it. “SerialPorts” defines settings related to the serial port. “Tools” has some utilities like PING or displays statistics. In “Exit” you may leave the menu or reboot the NetCom. At any time you can get a short hint by typing “H” for help.
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5.3.2. SERVER CONFIGURATION MENU
5.3.2.1. Parameter
ServerConfig +--------------------+ | Parameter | | Wireless | | OpenVPN | | Authentification | | Date & Time | | Info | +--------------------+
Image 61: Telnet Server Configuration
Server Parameter
Server Name [NetCom_0051100021 ]
MAC Address 00:04:D9:80:00:14 Interface Priority Cable, Wireless DHCP Enabled IP Address 192.168.1.81 Netmask 255.255.255.0 Broadcast 192.168.1.255 Gateway 192.168.1.1 DNS 192.168.1.3 Domain netcom.vscom.com.tw ConfigPort [23 ] PrintServerPort [515 ] KeepAlive Off KeepAliveInterval [0 ]
Image 62: Telnet IP-Configuration Parameters
Selecting “Parameter” brings up all Network configuration items, listed below.
Use the cursors to select the parameter you want to change. Hit <Enter> to go in edit mode. Type the new value.
“Server Name” identifies the device when the driver software searches for devices; this will help you find the correct NetCom server. ”Interface Priority” selects the network interface as
Wireless
or both.
Cable,
DHCP is for automatic IP configuration. “IP Address”, “Netmask” and “Broadcast” are parameters you get from your network administrator. Same applies to “Gateway”, “DNS” and “Domain”. The “ConfigPort” is 23 by default, which is standard for Telnet. You should only change it if you have strong reasons. ”PrintServerPort” is related to the new protocol of RFC1197, mostly referred to as »Line Printer Daemon«. ”KeepAlive” is the TCP-intrinsic function of connection checking. The related interval is defined in seconds.
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5.3.2.2. Wireless
ServerConfig +--------------------+ | Parameter | | Wireless | | OpenVPN | | Authentification | | Date & Time | | Info | +--------------------+
Image 63: Telnet Wireless Configuration
SSID [NetCom_0000123456 ] OperationMode Ad-hoc WirelessMode 11 b+g CountryRegion FCC (1-11) Channel 7
Encryption Type Off Encryption Key [empty]
RTSThreshold [2312] FragmentationThreshold [2312]
Image 64: Telnet Wireless Configuration Parameter
To operate a Wireless device, a lot of parameters are required. The configuration in the NetCom is reduced to a small set of them, for ease of configuration.
“SSID” is the «Service Set Identifier». This is used to get access to radio cells established by an Access Point. By default it is built from the serial number, as identification in Ad-hoc mode.
The “OperationMode” is selectable as between wireless stations, and also as
Ad-hoc for a direct connection
infra. This infra selects the
Infrastructure Mode, which is required to connect to an Access Point. Other wireless stations such as a PC or Laptop use the Access Point to transfer the data to the NetCom.
The “WirelessMode” is available as
11b and 11b+g. It may be
necessary to use the restriction of 11b when compatibility problems with other clients occur.
WLAN as of IEEE 802.11b/g define 11 possible channels (i.e. pre­defined frequencies) to use with WLAN devices. The available “CountryRegion” values is
FCC(1-11) for North America.
In Infrastructure Mode the NetCom
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adapts to the configuration of the Access Point. The “Channel” is used in Ad-hoc mode.
“Encryption Type” defines the encryption of the radio transmission. It
may be Off, WEP or WPA-PSK/TKIP. The WEP encryption may use 40 or 104 bit keys, sometimes also named WEP40/WEP64 or WEP104/WEP128. Which of this is required is defined by the “Encryption Key” Parameter. The key may be entered as ASCII characters, or as hexadecimal for a binary key. A string with 5 characters is WEP40 using an ASCII key. Using 10 characters as key defines this key as also WEP40, but with a binary key in hexadecimal notation. Likewise a 13 character string is WEP104 with ASCII, and 26 characters select WEP104 with a binary key.
WPA Encryption is available for the TKIP protocol. The key is PSK (Pre-Shared Key) and must be installed on all stations. It is recommended to use WPA-PSK/TKIP with a binary key, generated from random data.
“RTSThreshold” and “Fragmentation Threshold” are low level WLAN parameters. They should match the configuration in the Access Point. Higher values result in better data throughput. But when transmission error occur, the impact is dramatic. In this case lower values provide better security and better performance.
5.3.2.3. Encrypted Communication
Firmware version 2.2 introduces a way for encrypted communication with the NetCom Serial Device Server. This function establishes an encrypted VPN tunnel between your computer and the NetCom. All communication to the NetCom uses this new connection. No application requires a change of operation, but seamlessly gets the advantages of Encryption.
ServerConfig +--------------------+ | Parameter | | Wireless | | OpenVPN | | Authentification | | Date & Time | | Info | +--------------------+
Image 65: Telnet Wireless Configuration
To build this tunnel NetCom uses the Open Source product OpenVPN™ (http://openvpn.net
). This is the configuration of the parameters on the NetCom side. The function and the configuration of OpenVPN™ is described with more details later in the section of OpenVPN™ Client installation.
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OpenVPN Disabled TCP Port [1194 ] IP Address [192.168.127.254] Netmask [255.255.255.0] Broadcast [192.168.127.255] Max.Clients [8] TCP Port (Destination) [1194 ] IP Address (Destination) [0.0.0.0] Encryption None Logging Off
[ Generate Key ] [ Upload Key ] [ Stored Key ]
Image 66: Telnet OpenVPN Configuration Parameter
Of course “OpenVPN” may be Disabled, active as Server or in the combined
Server-Client
mode. When the function is active, the NetCom is virtually invisible on the IP-Address defined in
Server Parameter. It will still answer on ICMP, and also the Logging function is available. There is only one connection accepted by the NetCom, to the “TCP Port” defined for OpenVPN. There is nothing more available.
The “IP Address” is the local address on the VPN, it should be a private address. This VPN also has a “Netmask” and a “Broadcast” address, this is similar to the configuration of the “Server Parameter”. The Limit of “Max. Clients” specifies how many stations may establish simultaneous connections to the NetCom; it does not limit the number of installed clients. If OpenVPN™ is configured for Server-Client mode, it will establish a connection to a given Server, e.g. another NetCom. The “TCP Port” and the “IP Address” of the Destination are required.
Different grades of “Encryption” are available, from no encryption at all to AES with a 256 bit key. Select the required grade of security.
+---------------+ | None | | AES-128-CBC | | AES-192-CBC | | AES-256-CBC | +---------------+
Image 67: Telnet OpenVPN Encryption
If “Logging” is enabled, NetCom sends the messages of OpenVPN™ to the standard debug log output.
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The NetCom allows to “Generate” a new key from Random Data. This key is displayed in the terminal window. Depending on your terminal program, you need to have the logging capability active to save the data, or on other programs you may directly save the screen content.
Here is a sample key displayed.
# Please copy this key into a new text file.
-----BEGIN OpenVPN Static key V1----­0f3fc3d7d1d22d5b3ba1e498d27338c7 f8bf452edf484fae209d657b8cabfc58 9d2edb0c84eae68a65d6e93cda961775 1dbf8a7c38a73c9bc5f1a1ce0e0e0729 72b297945d6e0482a84f2397ab5ba8e6 00069892f0e41b8ab4a511d42ca6405c 8348f40652d8045962e8c0bcfc4c2b91 0ee7772be2b54ed0c0574acd9643d3b5 05a260ed54bd3ba730d12863b4f3df5a 4207b90562c6c7a9c27febabf6e0aa69 ebd04188729eed159c48a94a3da4a30e 7411c4ca2fca8afa365c535877dc00a5 306ddab341b0bf5b325be68b849294a5 47b69cc493aaf2329675f63953715952 558190b8964caf707b59801115413059 ea4b955d8f97263c233d280e032ba83e
-----END OpenVPN Static key V1-----
Image 68: Telnet Sample OpenVPN Key
Please note, this fresh new key is displayed. The configuration of the NetCom has not changed. When you exit this display with the <ESC> key, you are asked whether you want this key as the new key in your NetCom.
+------------------------------------------------------------+ | Should the generated key be stored as your new secret key? | | Yes No | +------------------------------------------------------------+
Image 69: Telnet use new Key
Select “Yes” to use this new key on the NetCom. As an alternative you may “Upload” any key to the NetCom, regardless of the source. Instead of loading a new key to the NetCom, it is also possible to “Show” the key currently used.
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5.3.2.4. Authentication
ServerConfig +--------------------+ | Parameter | | Wireless | | OpenVPN | | Authentification | | Date & Time | | Info | +--------------------+
Image 70: Telnet Access Authentication
Security Settings
Password [empty]
Image 71: Telnet Password Dialog
This menu allows to enter a password. This password is later required to get access to NetCom. It is also possible to leave the password empty.
5.3.2.5. Date & Time
ServerConfig +--------------------+ | Parameter | | Wireless | | OpenVPN | | Authentification | | Date & Time | | Info | +--------------------+
Image 72: Telnet Date & Time
Since Firmware version 1.6 the NetCom can retrieve actual date and time from a specified server.
Retype the value of “Date & Time” for manual setting. The format is
Date and Time Settings
Date & Time [01-01-1970 00:17:33 UTC+0]
Simple Network Time Protocol
State Off Mode DHCP Interval [1800 ] Server [ ]
Image 73: Telnet Date and Time Retrieval options
MM-YYYY HH:M
M:SS UTC+/-TZ
(Time Zone) The “State” field
has three possible settings:
- Off”: disables
DD-
automatic time
retrieval.
- Startup”: NetCom gets the time at reset or power on.
- Interval”: NetCom repeats to retrieve time.
The “Mode” field allows to decide how to configure the time server. It is either possible to get the server by
DHCP, or direct specified. The
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“Interval” defines how often the NetCom retrieves the time from the “Server”.
5.3.2.6. Info
ServerConfig +--------------------+ | Parameter | | Wireless | | OpenVPN | | Authentification | | Date & Time | | Info | +--------------------+
Image 74: Telnet Information
Info brings up general information about the device.
Server Info Server Type 413
Software Version 1.6.0 Hardware Version 1.0 Serial Nr. 0010100454
Contact [<unset> ]
Location [<unset> ]
Image 75: Telnet NetCom Server Information
This dialog displays some basic information about the installed NetCom server. The Administrator may provide some contact information here. “Contact” defines a person to contact for help, e.g. “Mrs. Jane Doe, 555-HELP”. “Location” is the physical place of the NetCom, e.g. “CeBIT Hall 12, Service Box IX.a”.
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5.3.3. SERIAL PORTS MENU
The settings available in this menu are by port. Therefore, first the port to configure has to be chosen.
SerialPorts
+----------+ | Port 1 | | Port 2 | | Port 3 | | Port 4 | +----------+
Image 76: Telnet Menu, select serial port for configuration
Just select the port by placing the cursor, and then press <Enter>.
5.3.3.1. Communication Parameters
SerialPorts +---------------------+ | Serial Settings | | Transfer Settings | +---------------------+
Image 77: Telnet Configure Communication Parameters
These settings come in effect in the case of the Raw connection type; i.e. if the Driver Mode is not used. The driver will configure the parameters as the application requested it.
The parameters are organised in two groups. The “serial settings” define the basic behaviour of the serial port. And the “Transfer Settings” configure the operation mode of NetCom on the network. Each serial port is configured separately, there is no setting shared between ports.
Serial Settings
Port Nr. 1 PortType (current) rs232 MaxBaudrate 921600 PortType rs232 Model 16950
Baudrate 38400
Manual 110 FlowType None DataBit 8 Parity None StopBit 1 RxFifoLength 2048 RxTriggerLevel [1248 ] TxFifoLength 2048 TxTriggerLevel [800 ]
Image 78: Telnet Serial transfer parameters
The NetCom devices allow to operate in RS232 and RS422/485 modes. This is configured by the Master DIP switches or by software,
+----------------------------+ | rs232 | | rs422 | | rs485byART-4-wire | | rs485byART-2-wire-echo | | rs485byART-2-wire-noecho | | rs485byRTS-4-wire | | rs485byRTS-2-wire-echo | | rs485byRTS-2-wire-noecho | +----------------------------+
Image 79: Telnet Op-Mode by Software
“PortType (current)” displays the
current setting. If the DIP switches are set for «
Selected by
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Software», the operation mode is chosen by the “PortType”
parameter.
The serial port is based on enhanced UARTs, the type and maximum speed are also displayed. These are hardware parameters, and can not be changed. The current UART “Model” may be virtually changed to a less advanced type. In some situations it may be desirable to deactivate the FIFO memory, or some other options.
When the NetCom is used via the Virtual Com Driver mode, the serial parameters are controlled by the application, which opened the serial port. However certain installations use a different operation, without Driver mode. Then the serial parameters must be defined separately. You may configure the serial transmission by setting “Baudrate” from a defined list. If you select
Manual in this list, you may enter it numeric
below. If the selected value is not possible, an error is displayed. Also configure character size, parity mode and the length of the stop bit.
The settings of “RxTriggerLevel” and “TxTriggerlevel” define when NetCom issues a “buffer empty/full” message. If the values are less than 16, they have direct impact on the handling of the serial port hardware FIFO. Also, if you change the UART “Model” to 16450, the FIFO size is configured to support a single Byte. This option reduces latency times, by increasing the network traffic.
FlowType +------------+
DataBit | None | Parity | RTS/CTS | StopBit | DTR/DSR | RxFifoLength | XON/XOFF | RxTriggerLevel | Advanced | TxFifoLength +------------+
Image 80: Telnet Standard Flow Controls
FlowType Configuration
Port Nr. 1 AutoCTS off AutoRTS off AutoDSR off AutoDTR off AutoTxXOnXOff off AutoRxXOnXOff off
Image 81: Telnet Advanced Flow Control configuration
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FlowType opens a submenu of configurations. Handshaking is available via Standard or
RTS/CTS. Also possible is the
use
DTR/DSR. There is also an
Advanced option for detailed and
XON/XOFF
customer specific configuration.
This
Advanced allows to
configure the flow control in a special menu. Every combination for incoming and outgoing flow control may be defined with this option.
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5.3.3.2. Data Transfer Modes
SerialPorts +---------------------+ | Serial Settings | | Transfer Settings | +---------------------+
Image 82: Telnet Configure Data Transfer Mode (TCP/IP)
Transfer Settings
Port Nr. 1
Mode Driver Mode
TCP Port(Control) [2000 ] TCP Port(Data) [2001 ]
KeepAliveMode On Connect KeepAliveInterval [0 ]
These are TCP/IP parame­ters. The TCP Port for “Data” transfers the serial data, while the TCP Port for “Control” transfers the control information defined by the VS NetCom driver, if installed. Programs operating in Raw TCP mode (like Telnet) connect to the “Data” port for data transfer. Since there are more transfer modes (listed below), all parameters are explained at
Image 83: Telnet TCP-Ports for Driver and Raw mode
Transfer Settings
Port Nr. 1
Mode +-------------------------+
| Driver Mode | TCP Port(Control) | Null Modem Tunnel | TCP Port(Data) | TCP Raw Server | | TCP Raw Client | KeepAliveMode | TCP Advanced Settings | KeepAliveInterval | UDP Mode | | IP Modem | +-------------------------+
Image 84: Telnet Available Transfer Modes
the “Advanced Settings”.
To change the current “Mode” of the serial port, place the cursor on the field and hit enter. A drop-down list of the available modes appears.
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For demonstration purposes the “TCP Advanced Settings” mode is selected. All parameters may be changed. This allows some unexpected
Transfer Settings
Port Nr. 1
Mode TCP Advanced Settings
Server On TCP Port(Control) [2000 ] TCP Port(Data) [2001 ] Max.Clients [1 ]
Client Off Destination [ ] TCP Port(Control) [2000 ] TCP Port(Data) [2001 ] Connect Triggered ShortHoldTime [0 ]
KeepAliveMode On Connect KeepAliveInterval [0 ]
Image 85: Telnet Parameters for transfer modes
configurations. Here this is used to show and explain all parameters and their purposes. Information is also available On-Screen when typing h for help.
NetCom usually acts as a network server. This means it accepts incoming connections. The most used Driver Mode is explained above. It is possible to disable this option by setting “Server” to
Off. Usually
there is only one client connection at a time, but the limit can be raised.
NetCom can also operate as a network client, but in most installations it does not. This is enabled by setting “Client” to On. In certain situations NetCom contacts a computer (server) defined by “Destination” to send data. Most customers just need a Raw TCP connection to the server. The target application is defined by the “TCP Port(Data)”. If the server is another NetCom, both devices can also exchange control information via the “TCP Port(Control)”. There are three types of “Connect”,
Permanent, Triggered and DSR. In Permanent mode NetCom
connects to the server immediately. If the connection is interrupted for some reason NetCom keeps trying until it is established again. In Triggered mode NetCom connects to the server when data arrives on the serial port. When no more data arrives, “ShortHoldTime” (in milliseconds) defines how long to keep the connect before closing it. Warning: a time shorter than 1000 may cause problems.
DSR is
controlled by the external device via the DSR signal. When the DSR becomes active at the NetCom, the connection to the target is established. As long as DSR is active the NetCom operates similar to
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the Permanent configuration. When DSR becomes inactive, the connection is terminated.
NetCom can monitor an open connection. This is controlled by the “KeepAliveMode”, which has three settings:
Polling. Please note, this option is effective only in Driver Mode and
Off, On Connect and
Null Modem Tunnel. If the Keep Alive function is required in the other modes, the global option in Server Parameters is available.
o
Off: no KeepAlives
o
On Connect: when a client is trying to connect to the server and
there was a connection before, the server checks if the first connection still exists. If it does not exist anymore, the server accepts the new connection
o
Polling: the server checks in “KeepAliveInterval” (seconds), if a
connection still exists.
There are predefined modes usable as compact configuration options. Listed and described below.
5.3.3.2.1. Driver Mode
In Driver Mode NetCom operates as a server. It accepts connections on the Data and the Control port. Both must origin on the same computer,
Mode Driver Mode
TCP Port(Control) [2000 ] TCP Port(Data) [2001 ]
KeepAliveMode On Connect KeepAliveInterval [0 ]
Image 86: Telnet Driver Mode parameters
5.3.3.2.2. TCP Raw Server Mode
Mode TCP Raw Server
TCP Port(Data) [2001 ] Max.Clients [1 ] Password [******]
Image 87: Telnet TCP Raw Server parameters
this is checked. The parameters for Keep Alive apply in driver mode. Only a single client computer is allowed at a time. The Control port set to zero is TCP Raw Server.
The NetCom also operates as a server in this mode. It only accepts raw data connections to the Data port (this is also
possible in Driver Mode). In Raw Server mode multiple clients may connect. Serial data received is sent to each client, all clients can send data. The customers application is responsible to avoid data confusion and damage.
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Firmware version 2.2 added the option of additional protection by “Password”. When a password is configured, the NetCom sends the question “Password: “ to the client. The user (his application) must first send the password, followed by a <CR> character. The password is not echoed to allow usage with Telnet on a Monitor.
5.3.3.2.3. TCP Raw Client Mode
Mode TCP Raw Client
Destination [ ] TCP Port(Data) [2001 ] Connect Triggered ShortHoldTime [0 ]
Image 88: Telnet TCP Raw Client parameters
In Raw Client Mode the NetCom is a network client. Under defined conditions it establishes a Raw
TCP connection to a pre-defined “Destination”. Since version 2.0 of the NetCom Firmware the Destination can hold multiple hosts as targets for a connection. They are entered as a comma separated list of DNS names or IP-Addresses. Each destination will have a TCP port number, separated by a colon. Instead of a single IP-Address or DNS name, a range of IP-Addresses is also valid. This range must be followed by the TCP port number, as in
192.168.254.12-192.168.254.17:2077. The Connect modes and Short Hold Time apply.
5.3.3.2.4. Null Modem Tunnel
Mode Null Modem Tunnel
Server TCP Port(Control) [2000 ] TCP Port(Data) [2001 ]
Client Destination [ ] TCP Port(Control) [2000 ] TCP Port(Data) [2001 ] ShortHoldTime [0 ]
KeepAliveMode On Connect KeepAliveInterval [0 ]
Image 89: Telnet Null Modem Tunnel parameters
This is a special
mode. Two NetComs
connect via network
and simulate a long
Null Modem cable
between the two
serial ports. This
mode is symmetric,
both NetCom operate
as server and as client
at the same time.
The server part operates in Driver Mode and waits for incoming connections. Serial data is transmitted, but also control and status signals on the serial port. The client part uses the three types of “Connect”,
Triggered and DSR.
Permanent,
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5.3.3.2.5. IP Modem
The serial port of a NetCom may mimic (emulate) a serial modem. This feature is available since Firmware version 2.0 of the NetCom. There is the separate section 8 below defining this functionality.
Mode IP Modem
TCP Port(Data) [2001 ] Destination [ ] IP Modem Config [ ]
Image 90: Telnet IP Modem Parameters
Here are the basic network parameters only. A modem accepts con­nections from the network, in this case via
TCP/IP. The TCP port for this is defined as the “TCP Port(Data)”. This is the only parameter required to set here. All other values are normally defined via AT-commands. However for short, “Destination” allows for up to four predefined targets, available with special Dial commands. The “IP Modem Config” is known as the Init String in standard modems.
5.3.3.2.6. UDP Mode
UDP is an Internet Protocol, which does not define a connection. There is no extra data to signal a successful transmission. As a side effect data may be sent and received faster than with TCP/IP. UDP is available since Firmware version 1.4.0
Transfer Settings Port Nr. 1
Mode UDP Mode
UDP Port(Local) [2002 ] Destination [ ] UDP Port(Dest) [2002 ] UDP MaxPacketSize [1458 ] UDP Timeout [0 ] UDP Trigger [ ]
Image 91: Telnet UDP Mode parameters
Please compare with the parameters for TCP Raw Server and Client Modes. The parameters to configure the UDP Mode are similar to a mixture of these modes. Since there is no
connection as in TCP/IP, it is required to configure the NetCom to receive data via UDP. The only parameter required is the local port number. To define where to send the data NetCom needs the Destination, and the port to address there. Since there is no connection, data can not be sent in a stream. UDP uses packages. There are several ways to define the content for a package. The maximum size of such a package may be defined. If this amount of serial data is received, a package is generated and sent. “UDP Timeout” (given in Milliseconds) is an interval. If no serial data is received for this time, all data available so far is sent as a package. A
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value of zero causes all data to be sent immediately. “UDP Trigger” defines a sequence of characters. As soon as this sequence is detected in the received data, all data up to the end of this Trigger is sent to the destination. In most situations such a Trigger includes control or other special characters. Enter them numeric: as \xHH where HH is the hexadecadic code of the character, or as \OOO where OOO is the octal code of the character. The backslash itself must be doubled as \\.
5.3.3.2.7. Print Server Function
Firmware Version 2.2 introduces the function as a Print Server according to RFC1179, also called a »Line printer daemon«. A print server is accessed through its IP Address via one specified TCP Port (see Parameter in 5.3.2 above). Data is handled in distinct queues, each with a certain name. Each queue is handled by a certain serial port, and the data is sent to the serial printer attached to this port.
Transfer Settings
Port Nr. 1 Mode Print Server
QueueName [lpd1 ] InitString [ ]
Image 92: Telnet Print Server Configuration
Each serial port configured for Print Server operation has its separate “QueueName”. The default value is »lpd« plus port number. The “InitString” is a
special feature of NetCom. This string is sent to the serial printer at the beginning of the next queued print job. The definition is in section 8.2.2.1 below.
5.3.4. TOOLS MENU
5.3.4.1. Ping
Tools +-------------+ | Ping | | Statistic | | Netstat | | Wireless | | Logging | | Firmware | +-------------+
Image 93: Telnet Tools menu
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The Ping tool allows for verification of network settings. Try to reach some hosts in your local network.
IP-Address to ping to: [192.168.1.42 ]
Image 94: Telnet Ping test utility
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5.3.4.2. Statistics
Tools +-------------+ | Ping | | Statistic | | Netstat | | Wireless | | Logging | | Firmware | +-------------+
Image 95: Telnet Statistics for serial ports
Tools
+----------+ | Port 1 | | Port 2 | | Port 3 | | Port 4 | +----------+
The Statistics are presented on a by-port base. So you first select the serial port, and then you have the information about modem status and control. Also the amount of data transferred is shown.
Line Status
DTR off (0) DSR off (0) RTS off (0) CTS off (0) DCD off (0) RI off (0)
Common
Serial Tx 0 Serial Rx 0
Image 96: Telnet Status and Statistics
5.3.4.3. Netstat
Netstat is a common tool to display the actual status of network
Tools +-------------+ | Ping | | Statistic | | Netstat | | Wireless | | Logging | | Firmware | +-------------+
Image 97: Telnet Netstat analysis
connections. It may be used to monitor the actual status of the NetCom.
This is a sample result of Netstat. When there is more to display, it will start with “1/2” in the first line. Or even more for a long list. You may change to a different page by using the Page Up/Down keys in your Telnet. The display is refreshed in an interval of some seconds. Use
ESC key to return to
the menu.
1/1 Proto Local Address Foreign Address State tcp 0.0.0.0:23 0.0.0.0:0 LISTEN tcp 0.0.0.0:80 0.0.0.0:0 LISTEN tcp 0.0.0.0:2000 0.0.0.0:0 LISTEN tcp 0.0.0.0:2001 0.0.0.0:0 LISTEN tcp 0.0.0.0:2010 0.0.0.0:0 LISTEN tcp 0.0.0.0:2011 0.0.0.0:0 LISTEN tcp 0.0.0.0:2020 0.0.0.0:0 LISTEN tcp 0.0.0.0:2021 0.0.0.0:0 LISTEN tcp 0.0.0.0:2030 0.0.0.0:0 LISTEN tcp 0.0.0.0:2031 0.0.0.0:0 LISTEN tcp 192.168.1.98:23 192.168.1.42:3665 ESTABLISHED udp 0.0.0.0:161 udp 0.0.0.0:33320 udp 192.168.1.98:10397
Image 98: Telnet Sample Netstat output
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5.3.4.4. Wireless
Tools +-------------+ | Ping | | Statistic | | Netstat | | Wireless | | Logging | | Firmware | +-------------+
Image 99: Telnet Tools Wireless Option
Act MAC SSID Ch Mode Enc X 3E:C4:73:F6:48:85 NetCom_0220100838 7 Ad-Hoc X 86:73:F6:22:E1:BA NetCom_0210100444 7 Ad-Hoc C2:4C:94:1B:AC:E0 NetCom_0230100152 7 Ad-Hoc 00:0F:B5:66:CF:56 NETGEAR 11 Managed X
Current Rate: 11Mb/s
Image 100: Telnet Sample WLAN Scan Output
When it comes to Wireless communications, it is useful to see a list of possible partner stations on the WLAN. This function is available in many drivers, and also in the NetCom WLAN Serial Device Servers. This function is often referred to as »Range Scan«. On the NetCom it will open a separate browser window with the results. An example of this is shown below.
This example lists three other NetCom configured for Ad-Hoc communication on channel 7. All of them use no encryption. There is also an Access Point (listed as Managed), of course in Infrastructure­mode. To connect to this AP the NetCom must use encryption.
Since the NetCom itself is in Ad-Hoc mode, the communication is limited to the 802.11b, which results in 11Mb/s as raw transmission speed.
The display is updated automatically when some information changes. Most noticeably this will be the “Act”-ivity sign.
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5.3.4.5. Logging
Tools +-------------+ | Ping | | Statistic | | Netstat | | Wireless | | Logging | | Firmware | +-------------+
Image 101: Telnet Syslog Option
Logging
Syslog Off Destination [ ] Facility [1 ]
Debuglog Off Debug Port [0 ]
Image 102: Telnet Syslog configuration
Since firmware version 1.6 the NetCom has two options of Logging. There is the standard Syslog, and a second option of logging via Telnet.
Activate the Syslog, and define the machine with the Syslog Demon running. Also configure the Facility parameter. You may also connect to a special “Debug Port”
5.3.4.6. Firmware
on the NetCom to get all messages in real-time.
Tools +-------------+ | Ping | | Statistic | | Netstat | | Wireless | | Logging | | Firmware | +-------------+
Image 103: Telnet Firmware Update
There is an option to upgrade the Firmware of NetCom. This is either done via the actual channel (i.e. the serial or Telnet connection). Or independently via a separate TCP/IP connection. This setting defines the parameter. The Firmware is sent coded in base64, via very simple programs like a second Telnet session, or similar tools.
Firmware Update
Update Port [2400 ]
[ Start Update ]
Image 104: Telnet Settings, Firmware Update via TCP/IP
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5.3.5. SAVE&EXIT MENU
5.3.5.1. Save Parameter
Save&Exit +------------------+ | Save Parameter | | Exit | | Reboot | +------------------+
Image 105: Telnet Save current Parameters
5.3.5.2. Exit
Save&Exit +------------------+ | Save Parameter | | Exit | | Reboot | +------------------+
Image 106: Telnet Exit from configuration
5.3.5.3. Reboot
You also leave the menu here. But the NetCom is restarted. This
Save&Exit +------------------+ | Save Parameter | | Exit | | Reboot | +------------------+
Image 107: Telnet Exit and Reboot
When some changes are done, it is possible to save these modified settings here. Confirmation is requested before doing this.
+---------------------------------+ | Do you want to save the changes | | Yes No | +---------------------------------+
You will not be surprised, when you leave the menu by selecting this option. If you made any changes of parameters, you must confirm to save these.
activates any changes in the settings. This reboot is necessary for some changes like IP configuration. Others do not require a reboot. Also here, if parameters are changed during the session, confirmation for saving them is requested.
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5.4. CONFIGURE NETCOM VIA SERIAL CONSOLE
In some situations it may be impossible to get network access to the NetCom Device. If this happens (e.g. by an accidentally misconfiguration), neither Telnet, nor the webinterface is functional. It may be even impossible to use the NetCom manager program.
In this case you must you must connect to the NetCom via the serial port. Disconnect any serial cable from NetCom. Set the DIP-Switches of port 1 to “RS-232 Configuration”, all switches to Off. Then connect the NetCom with your computer using a standard modem cable (direct connection). If you do not have a modem cable, use a Null Modem cable and plug the Null Modem adaptor to the serial port. On NetCom 211 or the rack mount versions you need a Null Modem cable anyway.
Open any serial terminal program (Hyperterminal, minicom, …), select 38400 bps, 8 Bit, No Parity as configuration. Set your terminal to emulate a VT 100 (recommended, but VT52 is also possible), including the Arrow keys.
When connected to NetCom you must define the type of terminal used. This is the same configuration option as described above in 5.3.1 Telnet Main Menu.
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6. THE VIRTUAL COM DRIVER
If properly configured, the serial ports of the NetCom Devices appear as virtual serial ports in your computer. The “virtual” means, there is no real hardware related to the serial port. However the driver offers the full functionality of a serial port to the system. The interface used by the driver is VCOMM, which in turn is supported by the Windows API. So Windows does not see a difference to Com1, and also no application should detect the change.
This section of the manual covers the correct installation of the drivers and serial ports. Please do a quick review of the section 4 Windows Driver Quick Installation, before reading further. As of the time of writing, the current driver is version 1.4.8.9
6.1. INSTALLATION OF NETCOM SERVERS
Image 108: Select NetCom to install
The NetCom Manager program is started by the Installation Wizard. Often there are more than only one NetCom listed. And sometimes not all of them are to be used on this specific computer.
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The “Exclude” button is used for that purpose. Select a NetCom Device, and click on that button. The driver will later ignore this NetCom, when
Image 109: Excluded NetCom
installing and operating the serial ports. The Icon changes to olive colour.
In “Image 108: Select NetCom to install” above you’ll notice yellow questions marks at each icon. These appear when the NetCom is not already installed for the Virtual Com driver. It may also appear, if you open NetCom Manager without administrative privileges. If the mark changes to a red exclamation mark, the NetCom is non functional. It may be without power, the network may be broken, or the device is completely removed. To clear the display in NetCom Manager just use the “Remove” button.
If a NetCom has not been operational when the Manager program was started, it is either displayed with the exclamation mark, or not displayed at all. You may make it operational be connecting it now. To install it, use the button “Search” to find it in the network now. Or “Add” it manually with that button.
Image 110: NetCom Manager Ports View
Similarly you may exclude certain ports on a specific NetCom Server from installation as a Virtual Com port.
These are the special options used while installing the driver software. At any time after installation the configuration may be changed by the NetCom Manager program. This may result in serial ports appearing in or vanishing from the system.
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6.1.1. CHANGING THE INSTALLATION
There are common situations, when the current configuration needs a change. In the first case the NetCom has been moved to a different location, or the logical structure of the network has changed. It may happen the IP-Address of NetCom is also changed. Either by Automatic (DHCP), or manually via a different interface like the Webbrowser. Because of the changed address the driver does not find the serial port to contact. Now open the NetCom Manager. It will re-detect the devices. In this process the Manager finds the already installed NetCom, but with a new configuration. Then the Manager requests
interaction from the user. This question here assumes the NetCom shall be installed from
Image 111: Reconfigured NetCom found
with a new number. If just a reconfiguration occurred, click on “No”. When you do that, the parameters of the installed Virtual Com are changed to contact the same serial ports on a new network address.
The second case occurs, when a NetCom is replaced by another device. This new device shall have the same configuration, especially the same IP-Address. When you start the NetCom Manager, it will detect a new device with parameters already in the database. So a similar question
appears. An installation of a new serial port is assumed again. If the device shall replace the old one, Click on the “No” button.
Image 112: Replaced NetCom found
In general the driver software and the NetCom Manager identify the NetCom Devices by the combination of IP-Address and serial number. If one of these is changed, the above requests appear.
scratch. This will produce a Com port
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6.2. CONFIGURE THE SERIAL PORTS
When the serial ports are installed by the Virtual Com driver software, any application may use them. In the Device Manager they appear as “NetCom COM Port” (Image 10: NetCom in Device Manager). Without special tests a program does not see a difference between Com1 and virtual Com7. For example the HyperTerminal program has no problem to communicate through these Virtual Com. And this situation is common amongst most programs.
A typical application selects a serial port, and opens it. After that it performs the standard configuration of bits per character, parity settings and number of stop bits. Also the flow control (handshaking) is defined by the application. Windows sends these requests to the port driver, and this driver sends the requests to the serial port on the NetCom.
Image 113: NetCom COM Port Serial Settings
The same parameters may be pre-configured in the Device Manager. This is done via the “Properties” of the “NetCom COM Port”. In the “Local Settings” tab these standard parameters are defined. Since most programs configure these parameters by themselves, the values are very rarely used. A typical situation is a serial printer attached to this virtual port.
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As usual this behaves different in Windows NT. There is no Device Manager. To change these standard parameters, open the “Ports” applet in the Control Panel.
However it is suggested you open the new “NetCom Manager” applet instead. Change to the “Ports” view as in Image 110: NetCom Manager Ports View. Double-click on the small icon at the left side. In this dialog go to the “Local Settings” tab, as seen above.
6.3. PERFORMANCE ISSUES
However operation through the network causes some extra time, which is approximately 5 Milliseconds. With a port internal to the computer this time may be just some 100 Microseconds. This has an impact on reaction times. Some data protocols may be sensible. A lot of configurations are possible to compensate for this. But these have an effect on the sheer data throughput of the virtual serial port.
Image 114: NetCom COM Port Performance Settings
Consequently the configuration starts on the “Performance” tab. There are four already defined sets of parameters. The default configuration is for “Best Performance”. The driver software and the NetCom communicate with big data blocks. As a result a reaction on short events on the serial port is somehow delayed. For applications operating
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with short data blocks, and waiting for short answers this is not optimal. It causes transmission delays, called Latency.
In three steps the Latency may be reduced, at the cost of reduced throughput for large data blocks. The fastest setting “Virtual FIFO Off” simulates a deactivated FIFO. The port is configured as if the FIFO is off, buffers are configured to never wait for a timeout, hence gaining in best reaction times. “Short Latency” mimics a 16C550 with full FIFO enabled, but no network timeouts will occur. Use the ”Driver Default” to get the standard setting.
Use “Advanced” to get access to detailed configuration.
6.4. NETWORK & MISC PROPERTIES
When you use the “Advanced” checkbox on the “Performance” tab, the “Network & Misc” tab opens automatically.
Image 115: NetCom COM Port Network & Misc Properties
The parameters on this tab control the operation of the driver software on the computer.
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“Tx Network Buffer Size”: If the application sends small chunks of data
to the driver, these are buffered to send them in one large packet. This defines the size of the buffer. And also the maximum packet size sent to the serial port by the driver software.
“Rx Network Buffer Size”: This is the size of the buffer to receive data
from the NetCom.
“Automatic Trigger”: based on internal rules, this checkbox selects a
best practice value for “Tx Trigger Level”. Deactivate it to control that parameter manually.
“Tx Trigger Level”: Controls the time when data is sent to the
NetCom. If the Tx buffer holds at least this amount of data, the driver immediately sends them. If there is less data, the driver
uses a timeout to determine when to send them. “Network Timeout (ms)”: This is the timeout. “Overspeed”: This is a special option, not really related to network
communication. There are old applications, limited in the
maximum speed. With Overspeed you define a multiplier. The
baudrate requested by the application is multiplied with this
factor. The result is sent to the NetCom to configure the serial
port. E.g. the application may be limited to 38,400 bps, but there
is a modem capable of 230,400 bps on the serial port. Set
Overspeed to a value of 6.000, and configure the application to
use 38,400 bps. “Open If Absent”: The NetCom may be used from a computer with a
DialUp connection. When this option is used, the driver will delay
the connection to NetComs serial port. Even when an application
opens the port, and configures the parameters, no data is sent. The
connection is established when data is sent to the NetCom, or
when status information is requested. “Keep Alive”: This option will periodically send control information to
the NetCom to check, if the connection is still operational. As a
side effect a DialUp connection will not automatically close. “Passive Modem”: This option controls how often the driver retrieves
Modem status information from the NetCom. If activated, the
driver never asks for the modem status. Instead the NetCom
informs the driver of any changes. If an application frequently
requests the Modem status, it gets the last value received. On slow
networks like the Internet this option is recommended.
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If inactive, the driver software retrieves the Modem status from
the NetCom serial port each time the application requests it. With
a maximum frequency of 10 per second. If the latest retrieved
information is not older than 100 milliseconds, this value is
returned. “Simulate Device Off on Connection Loss”: When this option is
enabled, the NetCom driver does not attempt to preserve
transmitted data. If on a normal serial port the connected device is
switched off, all data sent to this device gets lost. NetCom
simulates this behaviour. All data sent from the application to the
driver is discarded, when the TCP connection to the NetCom is
lost. The NetCom attempts to re-establish the connection in
regular intervals. When it is available again, data may be
transferred from then on.
6.5. REMOTE SETTINGS PROPERTIES
The other panel created by activating the “Advanced” checkbox on the “Performance” tab, is the “Remote Settings” tab.
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Image 116: NetCom COM Port Remote Settings Properties
NetCom 123 WLAN, 423 WLAN,
The parameters on this tab control the operation of the serial port on the NetCom Device. They are defined and activated by the driver software.
“Tx Trigger Level”: The serial port on the NetCom Device buffers data
for transmission to external devices. If the amount of data in this
buffer drops below this level, the NetCom is capable to receive
new data. It will send a related event to the driver software. “Rx Trigger Level”: When the serial port has received this amount of
data, these are sent to the driver on the connected computer. If the
amount is less than this, the NetCom applies a timeout of about 5
character times. This means the timeout varies with the serial
transmission speed. “Remote Flow Control” signals the NetCom to perform the handshake
on its own. This is necessary, because the network delay of some
milliseconds is to long for reliable operation in many situations.
To use this option, Firmware version 1.8.0 is required for the
NetCom. “Enable”: The configuration shown here is active, when the pre-defined
performance levels are used. When using the “Advanced” option,
Remote Flow Control is completely disabled. Enable as required. While it is best practice to configure as above, you can disable certain
events here. “CTS”, “DSR” and “Tx XON/XOFF” control the
output of data to the serial port. And “RTS”, “DTR” and
“Rx XON/XOFF” are used to stop transmission from the
connected device. An application has the option to use any
combination of these methods at the same time. The command to
use them is transferred to the NetCom. For example, if the port is
configured to use Hardware Flow Control, the NetCom will
control the RTS line, and observe the CTS line. If requested, any
of these methods may be unchecked. In that case the driver
software on the computer will control the lines. “Override App Settings”: In rare situations it is necessary to ignore the
applications configuration. Check this box, and select the
Flow Control to use with the device. “Limits”: These buttons are prepared for future software versions.
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7. UNINSTALLING THE SOFTWARE
The drivers and services install as usual. So it is easy to remove the drivers from the system. The entry is found in Control panel, section “Add/Remove Programs”. It is removed like other applications.
Image 117: Uninstall in Control Panel -> Add/Remove programs
You must confirm the uninstall operation and the devices are removed from the system. Further all driver and configuration files are removed from the Windows- and System-directories. A simple de-installation via the Device Manager may result in some driver files scattered in Windows.
There is also a separate uninstall item in the Start Menu. This is the same procedure as in the Control Panel. You are also asked to confirm the de-installation of the drivers.
Image 118: Uninstall in the Start Menu
Image 119: Confirm Uninstall of Drivers
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You may also start the Installation Wizard a second time. It will detect the installed drivers. The options are to Re-install the drivers, this is
similar to a repair installation. And it is possible to completely uninstall the current drivers.
Image 120: Installation Wizard to uninstall Drivers
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8. SPECIAL FUNCTIONALITIES
This chapter documents some functions and protocols, not directly related to the basic function of a serial port. There is the Modem Emulation by IP-Modem, the Print Server mode, and the encrypted communication by OpenVPN™.
The technical details of these operation modes are described in this separate section, because it would be to confusing to have the details in the description of the configuration menus.
8.1. IP MODEM FUNCTION
The Firmware version 2.0 brings the new function of IP Modem. Used in this mode, the serial port of the NetCom emulates a standard serial modem. Basically this means the NetCom will
a) answer to AT-commands on the serial port b) establish a connection to a destination c) inform the connected serial device of the connection d) accept a TCP connection, and inform the serial device of that
event
For connections the NetCom will use a TCP connection. This differs from a normal telephone line, so there will be some modifications in the behaviour. The target is an IP-Address, not a phone number. Also for hardware reasons the automatic baudrate detection used in today serial Modems is not available. However this is not a problem at all, the IP Modem can be installed in Windows as a Standard 33600bps Modem. Later there will be an INF-file for ease of installation.
8.1.1. SOME POSSIBLE SCENARIOS:
1. The customer has a remote management installation, operating via telephone line. These lines may be in-house or through public phone systems to other destinations. The customer wants to reduce costs for these lines, management and possibly hardware, using the Intra- or Internet.
2. The customer wants to contact several stations from a central server. Because of frequent target changes he does not want to define the target by a Virtual Com Port.
3. Remotely distributed devices contact a central system by Modem. This is the reverse of option 1.
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4. A computer without Network access shall have at least limited control on the connections established by a NetCom.
5. Old fashioned BBS installations become accessible via Internet. The typical multi-modem box is replaced by a NetCom Server with multiple ports configured for IP Modem operation.
8.1.2. SERIAL SIGNALS AND CABLES
A real modem provides the same signals as the serial port of a PC. However, where a signal is an output on the PC, it is an input to the modem, and vice versa. So in the NetCom the emulation of a modem must be incomplete. By exchanging RxD and TxD the data connection is fine, the same for handshaking RTS and CTS. The DTR of the PC is connected to DSR of NetCom, this is simple. The RI may be ignored, some connectors for serial ports also do that.
However a real modem provides DSR and DCD to the PC. There is only the DTR left on NetCom to serve these signals. In most configurations the NetCom-DTR serves as the DCD to the computer. The cable must provide a DSR to the PC then, e.g. by shortcut to the PC-DTR. In some configurations the NetCom-DTR must serve as the DSR. This is configurable by a command.
The recommended cable connects as shown in this table. Please note, this installation does not use the simply crossed signals. Especially the DSR of the PC is internally connected to the DTR of the PC.
DB9m PC IP-Modem DB9m DB9f
3 TxD ----- RxD 2 3 2 RxD ----- TxD 3 2 7 RTS ----- CTS 8 7 8 CTS ----- RTS 7 8 6 DSR PC-DTR (internal loop-back) 4 DTR ----- DSR 6 4 1 DCD ----- DTR 4 6 5 GND ----- GND 5 5
The limitation of signals is a restriction in function, compared to real world serial modems.
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8.1.3. OPERATION MODES BY IP MODEM
The function of IP-Modem may be configured port by port. On a NetCom with a single port there is no much of a difference. However a NetCom with two or more serial ports operates each port independently. In the following sections of this manual the phrase “serial port of a NetCom, configured to operate as IP Modem” is replaced by “IP Modem” for brevity.
Two basic operation modes are available. The first and default mode is Modem-to-Modem. This requires a serial port of a NetCom configured as IP Modem on both ends of the connection. When one IP Modem dials the other, the connection is established on the TCP level. Directly afterwards both IP Modems negotiate to ensure, they are a real NetCom IP Modem and are free for connection. If successful both issue a “CONNECT …” response to the serial connected devices. This is convenient for the customer to understand. The CONNECT may report some parameters, e.g. the minimum serial speed used by both Modems. These extra parameters are not implemented so far.
The other mode is named as Modem-to-Host. The destination is any software, which opens a TCP port for Listen. It may be a second NetCom configured for TCP Raw Server Mode. It may also be the customers application, running on a certain computer. This mode offers less features.
8.1.4. HAYES COMMANDS
The IP Modem operates with a command set similar to those in real Modems. All of the commands start with the character sequence ΑΤ.
8.1.4.1. AT command set
The following table lists many standard commands (in alphabetical order). The AT is omitted for brevity. The discussion of the functions is below the tables in section 8.1.5 below.
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8.1.4.1.1. Standard AT-Commands
These commands are based on the old Hayes Modem
AT Hayes-Standard IP Modem Function
A Answer Call Accept a connection Bn ITU-T modulation Define some modem operation modes Dnnn Dial connection,
basically phone number as nnn
Connect to the target system by IP-Address and TCP-Port. E.g. ATD10,0,8,42,2023 will “dial” to port 2023 on IP-Address 10.0.8.42
E Echo on/off Enable/Disable local echo of
command H0 Hang up Terminate the TCP connection. I Device Information I0 through I9 report information L Speaker Volume Ignored, always answered with OK M Speaker On/Off Ignored, always answered with OK N Auto serial speed N0 no Auto, N1 reports error O Return to data mode Q Result Codes Enable or disable result codes/strings S=nn/S? S-Register Set/request configuration registers V0/1 Responses Numeric/text responses to commands X Busy/Dial detect Ignored, always answered with OK Z Reset to User profile Standard
Table 7: IP Modem Standard AT-Commands
8.1.4.1.2. Extended AT-Commands
AT Standard-Extensions IP Modem Function
&C DCD control When to turn on DCD (by
IP-Modems DTR) &D DTR meaning Hang Up, Command Mode or Reset &F Load factory Default &K Flow Control &S DSR control When to turn on DSR (by IP-Modems
DTR) &V View Profiles &W Store Profile &W0/&W1 is “Standard”. ATZ1
loads profile 1
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&Zn=dd Save for short dial Define possible targets by DNS name
or IP-Address %C1 V.42bis enable Ignored \Q Flow control See &K
Table 8: IP Modem Extended AT-Commands
8.1.4.1.3. Non-AT commands
All these commands apply in Command Mode. If a Dial command succeeds with a CONNECT, the IP-Modem is in data mode. Every data received on the serial port is sent to the other station/IP Modem. And there is a special character sequence in Data Mode, which changes back to Command Mode. This sequence is +++ by default, with an interval of 1 second before and after this command; the three characters must appear in one second.
8.1.4.2. S-Registers for Configuration
Traditional there is a set of registers to control certain operations. These registers are controlled via the AT S-command mentioned above. This is a list of those supported by IP-Modem.
Reg. Function Range/units Default S0 Auto-Answer Ring 0-255 0 (no Auto-Answer) S1 Ring Counter 0-255 0 (read only) S2 Escape Code 0-127 (ASCII) 43 (= “+” for
“+++”) S3 Carriage Return 0-127 13 S4 Line feed 0-127 10 S5 Backspace 0-32, 127 8 S8 Comma pause 0-255 (seconds) Accept but ignore S9 Carrier detect response
1-255 (0.1 sec) 6
time
S12 Escape Guard time 20-255 (0.02
50 (= 1 second)
sec) S25 DTR Ready Delay 0-255 (0.01 sec) 5 (= 50 msecs) S26 RTS to CTS Delay 0-255 (0.01 sec) 1 (= 10 msecs) S30 Disconnect Timer 0-90 (seconds) 0 (read only,
AT\Tnn)
Table 9: IP Modem S-Registers for Configuration
S0 is frequently used to configure a modem to auto answer incoming calls. S1 may be checked by software if S0 is Zero, i.e. no
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Auto-Answer. S2 may be set to a different character, if the “+++” may happen in typical data. Otherwise the software must insert a pause in the transmission.
8.1.4.3. Sample Commands used by Windows
The NetCom IP Modem is intended for manual installation as kind of a “Standard Modem” in Windows. The reference is the MDMGEN.INF file. The commands used in that file are:
"AT&F", "ATA", "ATH", "AT &F E0 V1 &C1 &D2 S95=47 S0=0<cr>", "ATS0=0<cr>", "ATX4", "ATS7=<#>", "AT%C", "AT\N", "AT&K", "ATS30=<#>", "ATB", "ATDP", "ATDT", "ATL", "ATM"
8.1.5. DESCRIPTION OF AT-COMMANDS
The commands are listed more or less in a functional grouping. Configuration commands are listed also with their default settings in brackets.
8.1.5.1. AT D (dial)
This is the general Dial command. The target is defined as IP-Address plus TCP-port number. The dots in the address are replaced by a comma, and the TCP port is also separated by a comma. On normal modems a comma generates a pause in the dialling sequence. This is commonly required, so all software will support it; even multiple comma.
The modifiers “T” for Touch Tone and “P” for Pulse dialling have no direct equivalent on the TCP connection. They are used to change between Modem and Host mode, if the ATB command enables this (ATB2 or ATB3). Otherwise the IP Modem will ignore them.
Basically dialling is done to a given IP-Address plus a TCP port number. The IP-Address is given in decimal Octet format, where comma replaces the dot as the separator. This is followed by another comma, separating the TCP Port from the IP-Address. If the port is omitted, the target port is the same as the local TCP Data Port as defined in the configuration of IP Modem (see 5.1.2.2.5 or 5.3.3.2.5 above).
There are situations where the target is known by a DNS name. This name can not be used in a dial string, mostly because very few software will support it. So there is the option of dialling to a pre-defined entry by shortcut. This is given by an “S” followed by one or two digits. The shortcuts S90 to S99 are reserved; so far only S1 to S4 are
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implemented. Shortcuts are defined and saved by AT&Znn=<FDN:Port>.
All other non-numeric characters are understood as modifiers. The IP-Modem will simply ignore them. This especially applies to space characters. Typically dial strings are:
ATDT192,168,254,254,2003<cr>
Dial another IP Modem as a Modem-to-Modem
AT&Z12=demokit.vscom.com.tw:23<cr>
Define a shortcut for configuration port
ATDPS12<cr>
Dial the other IP Modem as Modem-to-Host
8.1.5.2. AT O (online / data mode)
If a connection is established, the IP Modem can still be in command mode. The ATO activates the transparent data mode.
8.1.5.3. AT A (answer call)
Have the IP Modem answer an incoming call, and establish a TCP connection. This command is required if Auto-Answer is disabled. Observe the operation mode defined by ATB.
8.1.5.4. AT B (modulation) [ATB1]
This command is used to define the modulation to use on the phone line. Since the only “modulation” available is IP, there is no choice. The command is used to change between Modem-to-Modem and Modem-to-Host mode.
ATB0 ATB1 ATB2
Modem-to-Host mode Modem-to-Modem mode, which is the default Modem-to-Modem when Touch Tone dialling, Modem-to-Host
when Pulse dialling. Answer in Modem-to-Modem.
ATB3
Modem-to-Modem when Touch Tone dialling, Modem-to-Host when Pulse dialling. Answer in Modem-to-Host.
8.1.5.5. AT E (echo) [ATE1]
Disable and enable the echo of the commands received. ATE0 to disable and
ATE1 to enable the echo.
8.1.5.6. AT Q (quiet) [ATQ0]
Configures the Modem to remain quiet. The Modem will not send any response messages to the serial port.
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8.1.5.7. AT V (verbose) [ATV1]
Responses as numeric values (ATV0) or as text strings (ATV1).
OK 0 CONNECT 1 RING 2 NO CARRIER 3 ERROR 4 CONNECT 1200 5 NO DIALTONE 6 BUSY 7 NO ANSWER 8
8.1.5.8. AT H (hangup) [ATH0]
Command to disconnect. Also used as ATH0. The related version ATH1 to just go off-hook is not supported, and reports an ERROR.
8.1.5.9. AT I(n) (information) [ATI0]
Report technical information about the IP-Modem. It is frequently used to identify the device. The answer is always sent as <cr><lf><#response#><cr><lf> <cr><lf>OK<cr><lf>. Here are the defined #response#-strings.
ATI or
230 230.4kbps maximum
ATI0 ATI1 ATI2 ATI3
100000000 100Mbps Ethernet
Version 1.0 / <compile-date> Version of
Modem-Firmware
ATI4 ATI5 ATI6 ATI7 ATI8 ATI9
ATI10 ATI11
Current Profile
NetCom 230k IP-Modem Device Identification
(<Name>\Serial#\IP-#:port\Com­X\NetCom)
Display serial port used
<very extended information>
8.1.5.10. AT S (setup)
Set and read the S-registers for configuration. ATSrr? is a request to read the current value, ATSrr=nnn stores the value nnn in the register rr. Unknown registers report ERROR. See Section 8.1.4.2 above for possible registers and parameters.
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8.1.5.11. AT L (loudness)
8.1.5.12. AT M (speaker)
These commands are answered with OK, but completely ignored. There is no function like speaker.
8.1.5.13. AT N (auto baud) ATN0
Automatic detection of serial speed. For hardware reasons this detection is not implemented. The command ATN0 is accepted and answered with OK. The ATN1 for automatic detection is not available, and answered with the ERROR response.
8.1.5.14. AT Z (reset)
Reset the configuration to a stored profile. IP Modem only supports profile 0 for simplicity. Same as ATZ0 or as AT&F or AT&F0.
8.1.5.15. AT &F (factory settings) [AT&F0]
This command has been designed as “Reset to Factory settings”, while ATZ simply meant reset. At time of invention users could change the default behaviour of their Modem, which was activated by ATZ. Nowadays the ATZ is ignored by many software. Instead AT&F is used, followed by complex initialisation strings. User may save profiles, which are selected by AT&F0 or AT&F1. There is no longer a documented way to revert to Factory Defaults.
While IP Modem itself has such a way, this is not usable to simply reset the configuration as Modem. So IP Modem will support only user profile 0, and it uses AT&F9 to really reset the user profile to the Factory defaults.
8.1.5.16. AT &C (DCD configuration) [AT&C1]
Configure the DCD signal to the PC. As IP Modem this signal may be generated by the DTR output. A standard modem can have DCD always on, and it can have the DCD follow the external carrier signal. When set to always on by AT&C0 the DCD may have a separate source. The DTR is free to serve as a DSR to the PC. The operation of DSR is defined by AT&S, so these commands are related. An
AT&C1
is the default, the DTR operates as DCD to the PC (this will require a cable connecting NetCom DTR to the DCD of the PC).
This command has priority over AT&S.
8.1.5.17. AT &S (DSR configuration) [AT&S0]
Configure the DSR signal to the PC. As IP Modem this signal may be generated by the DTR output. A standard modem can have DSR always on, as long as the Modem has power. Or it can have the DSR signalling
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whether the IP Modem is in command or in data mode. When set to always on by AT&S0 (this is the default) the DSR may have a separate source. The DTR is free to serve as a DCD to the PC. The operation of DCD is defined by AT&C, so these commands are related. An AT&S1 has DSR follow the data mode.
The AT&C has priority over this command. AT&S1 can only be effective, if AT&C0 is set.
8.1.5.18. AT &D (DTR configuration) [AT&D2]
Understand the DTR signal of the PC. The input on the IP Modem is the DSR, which requires a proper serial cable. Usually this signal is either ignored, or serves to disconnect from the phone line. There are four options:
AT&D0 Ignore DTR from PC
AT&D1
AT&D2 Toggle DTR to disconnect and enter command
Toggle DTR to enter command mode
default
mode
AT&D3 Toggle DTR to reset the IP Modem perform
ATZ
8.1.5.19. AT &K (handshake) [AT&K3] AT \Q [AT\Q3]
Configure serial Flow Control. AT&K0 and AT\Q0 disable all Flow Control. The default is AT&K3 and AT\Q3 to use RTS/CTS Hardware Flow Control between PC and IP Modem. AT&K4 and AT\Q1 configure for XON/XOFF Software Flow Control between PC and IP Modem. Other Options are not supported.
8.1.5.20. AT &V (view profile)
Show Profiles. This will display the current profile, the stored user profile, the short dial strings and the factory profile. Parameters are accepted but ignored. AT&V is AT&V0 and is AT&V1.
8.1.5.21. AT &W (save profile) Save the current configuration as user profile. AT&W is the same as AT&W0, all other commands report an ERROR.
8.1.5.22. AT &Z (save destination)
This command will save a destination in internet syntax. It is given by <host>:<port>. The <host> is either an IP-Address in dotted octet notation, or an FQN in correct syntax. The <port> is a string representing a decimal number. If :<port> is omitted, the target port is
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the local TCP Data Port as defined in the configuration of NetCom (see
5.1.2.2.5 and 5.3.3.2.5 above).
8.2. PRINT SERVER OPERATION
Sometimes the NetCom Serial Device Servers are used together with serial printers. These printers are available via a network to several stations for printing. So far there have been two operation modes to achieve this. First the serial port can operate as a TCP Raw Server, and the station just sends the data to print via a TCP connection. As second option a computer running Windows could install the driver for virtual serial ports. The printer is then controlled via this Com port. In both these solutions the buffering of data occurred on the client station.
Beginning with Firmware Version 2.2 the NetCom Devices offer a true Print Server mode, using the Line Printer Daemon protocol as of RFC1197. Here a print server (lpd) is a station with one IP Address and a single defined port to accept commands and data for printing. Several printers may be attached to the print server. Each printer has a separate data queue for management of print jobs. The data of the jobs is saved in this queue, instead of the client as before.
8.2.1. PRINTER QUEUE
The basic function of an lpd is to accept the data for printing, store it in a spooler queue, and send it to the printer when this is ready for printing. This is done for several queues in parallel. Each printer is identified by the name of the queue, where it is attached to. The NetCom Device Servers allow to configure a custom name for each queue, while the default name is »lpd« plus the number of the serial port (lpd1, lpd2, …). This name is set in the properties of the serial port.
When the lpd is running on a separate computer, the hard disk is used to save the data of the queues. The NetCom Servers neither have a mass storage device, nor huge amounts of memory. Each queue accepts at least one job with a size of up to 250 KB print data. If the job has more data, memory is either assigned dynamically to save the job, or the data is spooled through a ring buffer. Data is printed while the client still sends data. The amount of available dynamic memory depends on the number of ports in a NetCom Device Server, and the operations active on these ports.
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8.2.2. PRINTER RESET
Before a new job is sent to the printer, this printer should be in a well known state. On a parallel printer port this is easy to achieve. There is a defined signal to send a »reset« command to the printer.
Such a definition is not available for serial printers. Instead there is a reset command, which users may send via the serial line. Typically this command is specific to the manufacturer or even to the printer model. So the NetCom allows to specify this command by entering an “InitString” for each queue.
8.2.2.1. Init String Definition
The Initialisation of the printer typically involves ASCII control codes, ordinary ASCII characters and some binary data. On some models it may also be necessary to provide a certain state of the modem control signals RTS and DTR, applied with special timing. The “InitString” in the NetCom Device Serves offer all these options.
8.2.2.1.1. ASCII Text
Ordinary ASCII characters are entered as they are on the keyboard. The single exception is the ‘Less Than’ character ‘<’, which is used for other special functions.
8.2.2.1.2. ASCII Control Codes
ASCII control codes are entered by their standard name, enclosed in ‘Angle Brackets’, i.e. in ‘<’ and ‘>’ (Greater Than). Some examples of this are <ESC>, <CR> or <TAB>.
8.2.2.1.3. Numeric Codes
Especially binary data must be send by means of its numeric value. Since the ‘<’ ASCII character has a special function, the only way to use this is the numeric method. This also applies to printable characters of some Extended ASCII character sets.
The NetCom accept the decimal value, also enclosed in angle brackets. Up to three decimal digits define the character to send to the printer. The ‘<’ is used as <60>, while the <ESC> may also sent as <027>. The ‘>’ may be used directly, however for clarity <62> should be preferred.
8.2.2.1.4. Modem Control Signals
Via the “InitString” control of RTS and DTR is available. This manual does not make statements about voltage levels on the signals, these are just set to an active or inactive state. <RTS+> and <RTS-> activate and deactivate the RTS signal, while <DTR+> and <DTR-> do the same for DTR.
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8.2.2.1.5. Timing Options
Especially when using Modem Control signals it will be required to hold them in a given state for a defined amount of time. This may be done by applying a »Pause«-command in the “InitString”. The delay is given as numeric value in milliseconds (msec), preceded by a ‘P’. So <P50> causes the NetCom to wait 50 msec before proceeding with the next command or start printing. Up to three digits are possible. If more than 999 msec are required, the Pause-command must be repeated.
Please note: The delay is not executed as an exact time. NetCom guarantees to wait at least the required amount of time. The smallest delay possible is 10 msec, due to internal handling of date and time.
8.2.2.2. Reset Example
For example here is a hypothetic serial printer. The serial port operates at 1200 bps, 7 bit and even parity and 1 stop bit. For Reset the printer requires the command “<ESC>@0” sent with DTR and RTS off. When the data is transmitted, DTR must be on, and 50 msec later RTS must also be on.
Each character sent is 10 bits long, including the start bit. At 1200 bps each character needs 8.3 msec for transmission. So the transmission lasts for 25 msec. To be sure the control signals are active, an extra delay is applied after change of signals. The resulting string would be
<RTS-><DTR-><P10><ESC>@0<P35><RTS+><P50><DTR+>
The delay of 35 msec after the command data shall ensure, all data is completely transmitted to the printer.
8.2.3. OPERATION IN WINDOWS®
The Printer Server mode may be used to support serial printers in Windows® Operating System. This is a short instruction how to install and use it. Experience on installing printers in Windows is required for this instruction. First the installation of a new printer is given, the modification of an existing printer setup is described later.
8.2.3.1. Add a New Printer
From »Control Panel« open the »Printers and Faxes« windows. Select the »Add a printer« option. The usual »Add Printer« Wizard appears. Click the “Next” button to select the port, where the printer is attached to.
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Image 121: Add a printer
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