Comtrol Modbus Server User Manual

Modbus® Server
User Guide
Trademark Notices
Document Number: 2000535 Rev C
Comtrol, DeviceMaster, and PortVision are registered trademarks of Comtrol Corporation.
Ethernet is a registered trademark of Digital Equipment Corporation, Intel, and Xerox Corporation.
Modbus is a registered trademark of Schneider Electric.
Other product names mentioned herein may be trademarks and/or registered trademarks of their respective owners.
Third Edition, June 2, 2014 Copyright © 2010 - 2014. Comtrol Corporation. All Rights Reserved.
Comtrol Corporation makes no representations or warranties with regard to the contents of this document or to the suitability of the Comtrol product for any particular purpose. Specifications subject to change without notice. Some software or features may not be available at the time of publication. Contact your reseller for current product information.

Table of Contents

Modbus Server Application Overview ..............................................................................5
Recommended Chassis ................................................................................................................................. 5
Terms and Definitions .................................................................................................................................. 6
What is Modbus? ............................................................................................................................................ 6
Modbus/RTU (Supported by Modbus Server)............................................................................................ 6
Modbus/TCP (Not supported by Modbus Server)...................................................................................... 7
Modbus Server Functionality ..................................................................................................................... 7
Other Comtrol Modbus Solutions .............................................................................................................. 9
Modbus Router............................................................................................................................................ 9
Modbus/TCP - Multiple Modbus Master and Slave Types, Serial and Ethernet Raw/ASCII Devices 10
Installation Overview..........................................................................................................11
PortVision DX Overview ............................................................................................................................ 11
Installing PortVision DX............................................................................................................................ 12
Configuring the Network Settings .......................................................................................................... 15
Uploading Modbus Server ......................................................................................................................... 18
Installing the Serial Port Redirector (Optional).................................................................................. 19
Configuring Port Redirector COM Ports ............................................................................................... 21
Adding a Secure Port ................................................................................................................................ 21
Configuring the Secure COM Port........................................................................................................... 22
Embedded Web Pages..........................................................................................................25
Configuration Overview ............................................................................................................................ 25
Server Configuration (Main) Page .......................................................................................................... 26
Serial Interface Configuration Page....................................................................................................... 27
Edit Port Configuration Page................................................................................................................... 28
Edit Network Configuration Page........................................................................................................... 31
Embedded Diagnostic and Statistics Pages ...................................................................33
Known Modbus/RTU Device List Web Page .......................................................................................... 33
Serial Interface Communications Statistics Page ............................................................................... 34
Serial Interface Logs Page ........................................................................................................................ 36
Troubleshooting and Technical Support........................................................................37
Troubleshooting Checklist ....................................................................................................................... 37
General Troubleshooting........................................................................................................................... 38
Daisy-Chaining DeviceMaster 2E/4-Port Units.....................................................................................39
Technical Support ....................................................................................................................................... 40
DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C Table of Contents - iii
TableofContents
iv - Table of Contents DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C

Modbus Server Application Overview

This section defines the software functionality for the Modbus Server application and provides an overview of other Comtrol Modbus solutions (
The Modbus Server application was designed to provide enhanced connectivity for O
PC servers and applications that require Modbus/RTU communications. While standard gateways provide connectivity for only one application per serial port, Modbus Server provides connectivity for up to six applications per serial port.
Modbus Server was designed to greatly en Included are comprehensive device and port specific diagnostic web pages that display status, message response timing, timeout, and other error counts, and overall message statistics. A serial log is also included to provide message level diagnosis.

Recommended Chassis

The following table lists the recommended DeviceMaster UP chassis based on Modbus/RTU message throughput.
Page 9).
hance system maintenance capabilities.
Throughput 1-Port 2-Ports 4-Ports
Very High - Message rate of up to one message every 50 ms per port (20 messages per port per second)
High - Message rate of up to one message every 100 ms per port (10 messages per port per second)
Medium - Message rate of up to one message every 200 ms per port (5 messages per port per second)
Low - Message rate of up to one message every 500 ms per port (2 messages per port per second)
Very Low - Message rate of up to one message every second per port (1 message per port per second)
Latency
Transmit (From application to device) 2-10 ms (*)
Receive (From device to application 2-10 ms (*)
(*) = Based on one Ethernet TCP/IP connection per serial port running in a normal uncongested system. The maximum overall latency will increase as the number of Ethernet TCP/IP connections increase.
Note: T
hese estimates are based on a Modbus/RTU request and/or response message size of 20 bytes. Actual throughput will vary depending on message size and system requirements.
XX
XX X
XX X
XX X
XX X
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Modbus Server Application Overview - 5

Terms and Definitions

Terms and Definitions
This table provides Modbus Server definitions.
Term Definition

What is Modbus?

Master (or Client) Mode
Slave (or Server)
Modbus/RTU
Polling
Sockets
DeviceMaster DeviceMaster RTS or DeviceMaster UP.
The method of operation when a DeviceMaster or an application is operating as a Master or the message originator.
The method of operation when a DeviceMaster or an application is operating as a Slave or the message receiver.
The standard Modbus messages, in hexadecimal format, that are typically transmitted over serial lines but can also be transmitted over other communication methods such as wireless or Ethernet TCP/IP socket connections.
Note: Modbus/RTU over Ethernet TCP/IP is not the
same as Modbus/TCP.
The process where an application requests data on a continual basis. In this operation the Master sends the request messages while the Slave responds to the messages.
The method used to communicate between devices while communicating over Ethernet TCP/IP.

Modbus/RTU (Supported by Modbus Server)

Modbus/RTU is native Modbus in hexadecimal format. These are the base Modbus messages that contain simple read and write requests. The format is as follows:
Where:
The terms Master or Client are used to
The terms Slave or Server are used to identify the devices responding to the message.
Modbus/RTU is us
Serial port connectivity. RS-485 is th are also used.
Ethernet TCP/IP socket connections. This is not the same as Modbus/TCP (please see next section), but does provide a very simple method of interfacing to remote devices. It is used by many applications and some OPC servers. Note: This communication method is not used by PLCs.
ed for:
identify the sender of the message.
e most common, but RS-232 and RS-422
6 - Modbus Server Application Overview DeviceMaster Modbus Server User Guide: 2000535 Rev. C

Modbus/TCP (Not supported by Modbus Server)

Modbus/TCP (Not supported by Modbus
Server)
Modbus/TCP is an Ethernet network based protocol that contains a Modbus/RTU message, with the exception of the 2 byte CRC. The Modbus/TCP message contains a header with information designed to provide message identification and routing information. The format is as follows:
Where:
The terms Master or Client are used to
identify the sender of the message.
The terms Slave or Server are used to identify the devices responding to the message.
Modbus/TCP messages are typically sent to and received on a defined Ethernet TCP/IP socket of 502.
Modbus/TCP implementations provide more capability, but also require more processing than simpler Modbus/RTU implementations.
Modbus/TCP is used for connecting advanc
ed Ethernet based devices, such as
PLCs, HMIs, SCADA Systems, and most OPC Servers to:
Other Ethernet devices supporting Modbus/TCP.
Remote serial Modbus/RTU devices through gateways (such as the DeviceMaster UP).
Remote serial or Ethernet TCP/IP ASCII devices through a gateway (such as the DeviceMaster UP).
Note: Refer to the DeviceMaster UP for Modbus/TCP functionality.

Modbus Server Functionality

The Modbus Server application provides the following functionality:
Supports Modbus/RTU over Ethernet TCP/IP connections to the corresponding serial port through intelligent Modbus message handling and routing.
Supports only Modbus/RTU over Ethernet TCP/IP connections to a serial port.
Note: For Modbus/TCP functionality, refer the DeviceMaster UP
Supports up to six Ethernet TCP/IP connections to each serial port.
- One TCP/IP connection can be created with the Connect To connection
method.
-The Listen connection method accepts up to five or six connections,
depending if the Connect To connection is active.
Supports up to 255 Modbus devices per port. Both valid, (1-247), and reserved, (248-255), device Ids are supported.
Modbus/RTU specific message handling:
- CRC verification of all messages received on the TCP/IP and serial
interfaces.
- Timing out of responses from slave Modbus/RTU devices.
- Broadcast message handling on connected port only.
.
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Modbus Server Application Overview - 7
Modbus Server Functionality
System monitoring to ensure gateway operation:
- Gateway busy.
- Application message time-outs.
Advanced diagnostics web pages:
- Modbus/RTU device specific statistics and status. Up to 255 Modbus/RTU
devices per port can be monitored simultaneously.
- Serial port specific statistics, response timing, and status.
- Serial port message logging.
Combined with a serial port redirector, such as the Comtrol Secure Port Redirector, which can support up to six COM port connections to each serial port.
8 - Modbus Server Application Overview DeviceMaster Modbus Server User Guide: 2000535 Rev. C

Other Comtrol Modbus Solutions

Comtrol provides several other Modbus solutions other than Modbus Server that include:

Modbus Router

Modbus/TCP
Other Comtrol Modbus Solutions
Modbus Router Modbus Router firmware was developed to prov
Modbus connectivity from a wide variety of Modbus masters to a wide variety of local and remote Modbus slaves. Advanced features include master-to-master communication, private serial bus connectivity, write protection, and device ID aliasing. With simplified configuration pages and advanced routing, Modbus Router provides unmatched Modbus connectivity.
ide innovative network-wide
Modbus Router firmware supports the
following controllers:
Modbus/TCP masters
Modbus/RTU and Modbus/ASCII serial masters
Modbus/RTU and Modbus/ASCII over Ethernet TCP/IP masters
Modbus Router firmware supports the following devices:
Modbus/TCP slaves
Modbus/RTU and Modbus/ASCII serial slaves
With additional gateways, both remote Modbus serial slaves and raw/ASCII devic
es Modbus Router firmware is recommended in installations that require:
Local (directly attached) Modbus master
and/or slave connectivity
No local raw/ASCII device connectivity
Automatic Modbus protocol translations (if needed)
Connectivity to remote Modbus slave(s) and/or raw/ASCII device(s)
Connecting single or multiple Modbus masters to the slave device(s)
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Modbus Server Application Overview - 9

Modbus/TCP - Multiple Modbus Master and Slave Types, Serial and Ethernet Raw/ASCII Devices

Master-to-Master connectivity (via Shared Memory subsystem)
Isolation of serial Modbus slaves (via Private Serial Bus connectivity)
Write protection of serial Modbus slaves
Modbus Device ID conflict resolution
Modbus/TCP ­Multiple Modbus Master and Slave Types, Serial and Ethernet Raw/ASCII Devices
The Modbus/TCP firmware has been designed to provide great flexibility for connecting both Modbus serial slaves and raw/ASCII devices to a variety of Modbus controllers and applications.
Such advanced raw/ASCII options as filtering
, command/response mode, peer-to­peer Modbus communications and simultaneous connections to multiple Modbus controllers and/or Ethernet TCP/IP applications make the Modbus/TCP firmware the flagship of all Modbus to raw/ASCII gateways.
Modbus/TCP firmware supports the
following controllers:
Modbus/TCP masters and slaves
Modbus/RTU and Modbus/ASCII serial masters and slaves
Applications over Ethernet TCP/IP connections (raw/ASCII only)
Modbus/TCP firmware supports the following devices:
Raw/ASCII devices, both serial and Ethernet T
CP/IP, such as barcode
scanners, vision systems, RFID readers, weigh scales, encoders and printers
Modbus/RTU and Modbus/ASCII serial slaves
Modbus/TCP firmware is recommended in installations that require:
Connectivity to serial and/or Ethernet TCP/IP raw/ASCII devices
Connectivity to Modbus/RTU and/or Modbus/ASCII serial devices
Connectivity from single or multiple Modbus masters and/or applications to
the devices
Automatic Modbus protocol translations (if needed)
10 - Modbus Server Application Overview DeviceMaster Modbus Server User Guide: 2000535 Rev. C

Installation Overview

Hardware Installation
Documents
Web
DeviceMaster UP Installation and Configuration Guide
DeviceMaster UP Hardware Installation and Configuration
Use this section to locate software and installation documentation for the DeviceMaster UP to quickly install and configure Modbus Server.
An installation follow
1. Connect the DeviceMaster UP to
the network.
If necessary, use the appropriate hardware installation document for your DeviceMaster UP.
2. Install PortVision DX. You can
refer to the PortVision DX
Overview subsection to locate
PortVision DX and install it easily.
3. Configure the DeviceMaster UP network settings using PortVision DX
(Configuring the Network Settings
4. You must upload the Modbus Server firmware into the DeviceMaster UP
using PortVision DX (Uploading Modbus Server
5. Configure the port characteristics using the DeviceMaster UP embedded web
page (Embedded Web Pages
6. Optionally, install the secure COM port redirector if you require COM port
support (Installing the Serial Port Redirector (Optional)
7. Connect any serial device or devices using the appropriate hardware
installation document for your DeviceMaster UP (table, above).
s these basic steps.
on Page 15).
on Page 18).
on Page 25).
on Page 19).

PortVision DX Overview

Use PortVision DX to identify, configure, update, and manage the DeviceMaster UP on the following operating systems:
Windows XP
Windows Server 2003
Windows Vista
Windows Server 2008
Windows 7
Windows Server 2012
Windows 8/8.1
PortVision DX requires that you connect to the same network segment as the Windows host system if you want to be able to scan and locate it automatically during the configuration process.
Before installing PortVision DX, consider the following:
Use PortVision DX to upload firmware and apply changes to a DeviceMaster
that is on the same local network segment as the system on which PortVision DX is installed. You cannot apply changes through PortVision DX to a DeviceMaster that is not on the same local network segment.
the Comtrol Ethernet-attached product
DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C Installation Overview - 11
Installation Overview
Use PortVision DX to monitor any DeviceMaster on the network. The
DeviceMaster does not have to be on the same local network segment as PortVision DX for monitoring purposes.

Installing PortVision DX

PortVision DX requires that you connect the DeviceMaster UP to the same network segment as the Windows system during the configuration process.
1. If necessary, download the latest version of PortVision DX from
ftp://ftp.comtrol.com/dev_mstr/portvision_dx/
2. Execute the PortVision_DX_[version].msi file.
3. Click Next on the Welcome screen.
.
4. Click I accept the terms in the License Agreement and Next.
12 - Installation Overview DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C
Installing PortVision DX
5. Click Next or optionally, browse to a different location and then click Next.
6. Click Next to configure the shortcuts.
7. Click Install.
DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C Installation Overview - 13
Installation Overview
8. Depending on the operating system, you may need to click Ye s to the Do you
want to allow the following program to install software on this computer?
query.
9. Click Launch and Finish in the last installation screen.
10. Click the Scan button in the Toolbar so that PortVision DX locates the
DeviceMaster UP.
Note: PortVision DX locates all DeviceMaster models, including: the
DeviceMaster 500, DeviceMaster LT, DeviceMaster PRO, DeviceMaster RTS, DeviceMaster Serial Hub, and DeviceMaster UP.
14 - Installation Overview DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C

Configuring the Network Settings

Default Network Settings
IP address:
192.168.250.250
Subnet mask:
255.255.0.0
Gateway address:
192.168.250.1
11. Select the products for which you want to scan. If you do not have any
RocketLinx managed switches or IO-Link Masters it saves scanning time if you do not scan for them..
Note: If the Comtrol Ethernet-attached product is not on the local segment and it
has been programmed with an IP address, it will be necessary to manually add the Comtrol Ethernet-attached product to PortVision DX.
12. Go to Step 5
in the next section, Configuring the Network Settings, to program
the DeviceMaster UP network settings.
If you need additional information about PortVision DX, refer to the Help system.
Configuring the Network Settings
DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C Installation Overview - 15
Use the following procedure to change the default network settings on the DeviceMaster UP for your network.
Note: T
echnical Support advises configuring one new DeviceMaster UP at a time
to avoid device driver configuration problems.
The following procedure shows how to configure a single DeviceMaster
UP
connected to the same network segment as the Windows system.
1. If you have not done so, install PortVision DX (Installing PortVision DX on
Page 12).
2. Start PortVision DX using the PortVision DX desktop shortcut or from the Start
button, click Programs > Comtrol, > PortVision DX.
3. If this is the first time you have opened PortVision DX, click the Scan button in
the Toolbar.
4. Select the products for
which you want to scan. If you do not have any RocketLinx managed switches or IO-Link Masters it saves scanning time if you do not scan for them..
Note: If the Comtrol Ethernet-
attached product is not on the local segment and it has been programmed with an IP address, it will be necessary to manually add the Comtrol Ethernet-attached product to PortVision DX.
Installation Overview
5. Highlight the DeviceMaster for which you want to program network
information and open the Properties screen using one of these methods.
Double-click the DeviceMaster in the Device Tree or Device List pane.
Highlight the DeviceMaster in the Device Tree or Device List pane and click the Properties button.
Right-click the DeviceMaster in the Device Tree or Device List pane and click Properties in the popup menu
Highlight the DeviceMaster, click the Manage menu and then Properties.
Note: See the PortVision DX Help system for information about using
PortVision DX.
16 - Installation Overview DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C
Configuring the Network Settings
6. Optionally, rename the DeviceMaster UP in the Device Name field.
Note: The MAC address and Device Status fields are automatically populated and
you cannot change those values.
7. Optionally, enter the serial number, which is on a label on the DeviceMaster.
8. If necessary, you can change the Detection Type.
REMOTE means that the DeviceMaster is not connected to this segment of the network and it uses IP communications, not MAC communications.
LOCAL means that the DeviceMaster is on this local network segment and uses MAC communications. An IP address is not required but Technical Support recommends using an IP address.
9. Change the DeviceMaster network properties as required for your site.
Do not select this option to run the DeviceMaster in MAC mode. The DeviceMaster does not support MAC mode.
To use the DeviceMaster with DHCP, click DHCP IP, and make sure that you provide the MAC address of the device to the network administrator. Make sure that the administrator reserves the IP address, subnet mask and gateway address of the DeviceMaster in the DHCP server.
To program a static IP address, click Static IP and enter the appropriate values for your site.
10. Click Apply Changes to update the network information on the DeviceMaster.
11. Click Close to exit the Properties window.
DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C Installation Overview - 17
Installation Overview

Uploading Modbus Server

Use this section to upload Modbus Server on the DeviceMaster UP using PortVision DX.
1. Make sure that you download the latest Modbus Server version.
2. Execute the .msi to unpackage the Modbus Server firmware file.
3. If necessary, open PortVision DX > Start/Programs > Comtrol > PortVision DX
> P
4. Rig click Advanced > Upload Firmware, browse to the Modbus Server .cmtl fi then
o
rtVision DX or use the desktop shortcut.
ht-click the DeviceMaster or DeviceMasters for which you want to load,
le and
click Open.
5. Click Ye s to the Upload Firmware message that warns you that this is a sensitive process.
18 - Installation Overview DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C
It may take a few moments for the firmware to upload onto the device. The device will reboot itself during the upload process.
6. Click Ok to the advisory message about waiting to use the device until the status reads ON-LINE. In the next polling cycle, PortVision DX updates the List View pane and displays the new Modbus Server version.

Installing the Serial Port Redirector (Optional)

If your environment requires COM port support, you can install the Comtrol serial port redirector using the following procedure.
1. If you have not done so, download the serial port redirector.
2. Execute the .msi file and click Next.
Installing the Serial Port Redirector (Optional)
3. Click I accept the terms in the License Agreement and then click Next.
4. If desired, Browse to another installation location or click Next.
DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C Installation Overview - 19
Installation Overview
5. Click Next to the Configure Shortcuts screen.
6. Click Install.
7. Click Finish.
20 - Installation Overview DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C

Configuring Port Redirector COM Ports

Use the following procedures to:
Add a DeviceMaster UP port
Configure the port for the secure port redirector
If necessary, refer to the secure port redirector help
Configuring Port Redirector COM Ports
system for more information.
Adding a Secure Po
rt
Use the following procedure to add a secure port or ports.
Note: You must have enabled the security feature in SocketServer and have the IP
address and TCP port numbers and enabled the TCP Connection for each port before performing the following procedure.
1. If necessary, open the Secure Port Redirector, click Start, Programs, Secure Port Redirector, and Secure Port Redirector.
2. Click Port and Add.
3. Select an available COM port in the Virtual serial port drop list.
4. Click Client or Server depending on the COM port requirements.
5. Enter the Remote IP address of the DeviceMaster UP.
6. Enter the TCP port number for which you want to communicate on the DeviceMaster UP.
7. Click Ok.
8. Repeat Step 2
for each port that you
want to use as a secure COM port.
DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C Installation Overview - 21
Installation Overview

Configuring the Secure COM Port

Use the following procedure to configure the port.
1. Double-click the port that you want to configure.
2. Optionally click the Connection
Settings tab, click Auto-reconnect when connection is broken, set the
Reconnect interval, set Cache data when the connection is broken,
and then Ok.
3. Click the SSL Security tab and then click Use SSL for connection to remote side.
22 - Installation Overview DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C
Configuring the Secure COM Port
4. Click the Settings tab and select the appropriate serial port settings.
5. Optionally, click the Extra Strings tab and enter the appropriate values.
6. Click OK to save the settings for the DeviceMaster UP.
7. Repeat the above procedure for each port that you want to use as a secure COM port.
8. Close the Secure Port Redirector window when you are done.
You are now ready to connect the serial devices to the DeviceMaster UP ports.
DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C Installation Overview - 23
Installation Overview
24 - Installation Overview DeviceMaster UP Modbus Server User Guide: 2000535 Rev. C

Embedded Web Pages

All configuration and status information is provided through embedded web pages for Modbus Server.
Note: T
For firmware installation and setup information, see
Page 11 or the PortVision DX help system.
This section discusses the following:
Configuration overview (below)
Server Configuration (Main) Page
Serial Interface Configuration Page
Edit Port Configuration Page
Edit Network Configuration Page
See the Embedded Diagnostic and Statistics Pages (Page 33) section for information about locating diagnostic and

Configuration Overview

he latest Modbus Server firmware must be installed before you can
configure network or serial/socket port characteristics.
Installation Overview on
on Page 26
on Page 27
on Page 28
on Page 31
statistics for Modbus Server.
The following overview shows how to access the DeviceMaster Server Configuration embedded web page and configure serial device interfaces.
Note: If you have not configured the network information into the DeviceMaster
during initial setup, you must configure the network information before configuring port characteristics.
1. From PortVision DX, highlight the DeviceMaster that you want to configure and select Web page.
2. Optionally, enter the IP address of the device in the Address box of your web browse.
3. Select Serial Interface Configuration.
4. Select the appropriate port to access the Edit Port Configuration page for that port.
5. Change the serial port configuration properties as required for your site.
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Embedded Web Pages - 25

Server Configuration (Main) Page

Server Configuration (Main) Page
Access the main DeviceMaster web page (Server Configuration) from P
IP address of the DeviceMaster in the Address box of your web browser.
The Serv software version and current network configuration for the DeviceMaster.
In addition, the Server Configuration pa to the configuration, statistics, and diagnostics pages, which are discussed in the table below.
Sof
IP Config
IP Address IP Netmask IP Gateway
Serial Interface Configuration
Communication Statistics
Display Serial Logs
Configure Network
Display All Known Modbus/RTU Devices
Reboot Reboots the DeviceMaster.
er Configuration page displays the
Server Configuration Page
Modbus Server firmware
tware
version currently running on the DeviceMaster.
Type of IP configuration currently in use (static or DHCP).
IP address, netmask, and gateway configured in the DeviceMaster.
Opens the Serial Interface Configuration Page (Page 27), which provides an overview of the serial interface settings and provides access to the Edit Port Configuration page for serial port configuration on the selected port.
Opens the Serial Interface
Communications Statistics Page (Page 27), which contains
serial interface and application connection statistics.
Opens the Serial Interface Logs Page (Page 36), which contains the statistics and error reporting information for each port.
Opens the Edit Network Configuration Page (Page 31), which can be used to modify DeviceMaster network configuration after initial configuration using PortVision DX.
Opens the Known Modbus/ RTU Device List Web Page (Page 33), which displays all known Modbus/RTU device attached to all serial ports.
ortVision DX or enter the
ge links
26 - Embedded Web Pages DeviceMaster Modbus Server User Guide: 2000535 Rev. C

Serial Interface Configuration Page

The Serial Interface Configuration p
provides:
Links to the following pa
ges:
- Server
Configuration (Main) Page (Page
26)
- Serial Interface
Communications Statistics Page
(Page 34)
- Serial Interface
Logs Page (Page
36)
- Known Modbus/
RTU Device List Web Page (Page 33)
for all ports or a specific port. Clicking the
Display Devices (all) link or the
Display Devices for a specific port.
Access to the Edit Port Configuration page for each port (Port #)
An overview of serial device configuration settings for each port, which displays the current settings
Note: The Application
TCP Connection Status displays the Remote Connections.
Up to six active TCP/IP connections for each serial port may be displayed at one time.
To change any settings for a port, select the corresponding Po
age
Serial Interface Configuration Page
rt # link, which opens
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Embedded Web Pages - 27

Edit Port Configuration Page

Select the appropriate serial
port number to configure the
serial port characteristics.
the Edit Port Configuration page.
Edit Port Confi
guration Page
Use the Edit Port Configuration page to change a serial port’s configuration parameters.
To access the Edi
t Port Configuration page, select the appropriate port number
link (for example, Port 1) on the Serial Interface Configuration page.
Use the Seria
l Configuration area of the Edit Port Configuration page to configure
serial port characteristics for the device that you plan on connecting to the port.
28 - Embedded Web Pages DeviceMaster Modbus Server User Guide: 2000535 Rev. C
Name Value(s) Description
Serial Configuration
All models, except 2-port models:
RS-232 (default)
•RS-422
•RS-485
Mode
2-port models:
Selectable serial mode of communications.
RS-232 (default)
•RS-422
RS-485_2-wire
RS-485 4-wire Master
RS-485 4-wire Slave
300, 600, 1200, 2400,
Baud Rate
4800, 9600, 19200, 38400 (default), 57600, 115200,
Selectable serial port baud rates.
230400
None (default)
Parity
Even
Selectable parity values.
Odd
Data Bits 5, 6, 7, 8 (default) Selectable data bit values.
Stop Bits 1(default) or 2 Selectable stop bit values.
None (default)
Flow
RTS/CTS
XON/XOFF
Selectable flow control values.
Half-Duplex
Receive time-outs between packets in milliseconds. This is the maximum spacing between received bytes allowed before
Rx Timeout Between Packets
0-65535
(default = 50)
Modbus/RTU messages/responses received over both the serial and Ethernet TCP/IP interface are expected to be complete.
Note: If this value is set too low, incomplete
and/or invalid Modbus/RTU messages may be incorrectly detected.
Duplicate Serial Configuration For All Ports
N/A
If selected, will apply the serial port configuration to all serial ports.
Modbus/RTU Protocol Settings
Device Response Timeout
0 to 65535 ms.
(Default=1000 ms)
The maximum allowable time for a slave Modbus/RTU to respond to a message before the message is considered timed out.
Edit Port Configuration Page
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Embedded Web Pages - 29
Edit Port Configuration Page
Name Value(s) Description
Discard Rx Packets With Errors
Duplicate Modbus/ RTU Protocol for All Ports.
Application TCP Connection Configuration
Enable
Listen
Listen Port
Connect to Mode
Connect Port
Connect IP Address
Disconnect Mode
Idle Timer
On/Off
(Default = On)
N/A
On/Off
(Default = On)
On/Off
(Default = On)
1-65535
Default:
Port 1=8000
Port 2=8001
Port 3=8002
..
..
Port N =800N -1
Never
Connect-Always
(Default = Never)
1 to 65535
(Default=0)
Standard IP address format:
xxx.xxx.xxx.xxx
Never
Idle
(Default = Never)
1 to 65535
(Default=0)
If selected, the DeviceMaster will drop all packets received with parity, framing, or overrun errors.
Note: Modbus/RTU messages with invalid
CRCs will always be discarded independent of this setting.
If selected, will apply the Modbus/RTU protocol settings to all serial ports.
If selected, this TCP/IP socket interface will be enabled.
If selected, the TCP/IP socket interface will listen for a connection at the specified Listen
Port.
If Enable and Listen are both selected, allows acceptance of:
Up to six connections from external applications if there is no active Connect-to connection.
Up to five connections if there is an active Connect-to connection.
If Enable is selected, this setting determines how to connect to an application.
If Never, do not attempt to make a connection.
If Connect-Always: Always attempt to maintain a connection to the application at Connect IP Address and Connect Port.
Socket port to connect to. Used in conjunction with Connect to Mode and Connect IP Address.
IP Address of application to create a connection. Used in conjunction with Connect to Mode and Connect Port.
Mode on which to disconnect from the application.
Never – Will not disconnect when connection(s) are idle. (Typically used in
Listen and Connect-Always modes.)
Idle – Utilizes the
Idle Timer t
o determine
when to close the connection.
If the Disconnect Mode is set to Idle, the idle or inactivity time when the connection(s) will be closed.
30 - Embedded Web Pages DeviceMaster Modbus Server User Guide: 2000535 Rev. C

Edit Network Configuration Page

You can use the Edit Network Configuration page to change the DeviceMaster network configuration after using PortVision DX for initial network configuration.
Use the following procedure to chan
1. Select the IP configuration type (Use DHCP or Use St
2. If you select Use Static configuration below, enter a valid IP address, subnet mask, and IP gateway for your network. The network information is programmed into the DeviceMaster after applying the changes and rebooting the device. If necessary, see your network administrator for a valid IP address.
Note: The DeviceMaster family default IP address is 192.168.250.250, default
subnet mask is 255.255.0.0, and the default IP gateway is
192.168.250.1.
3. Select Save or Undo Changes to close the page.
4. If you selected Save, select Reboot to program the network information into the DeviceMaster or Continue if you want to reboot later.
Note: Changed network settings will not take affect until the DeviceMaster is
rebooted.
Edit Network Configuration Page
ge the network configuration.
atic configuration below:).
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Embedded Web Pages - 31
Edit Network Configuration Page
32 - Embedded Web Pages DeviceMaster Modbus Server User Guide: 2000535 Rev. C

Embedded Diagnostic and Statistics Pages

This section discusses embedded diagnostic and statistics web pages for Modbus Server.

Known Modbus/RTU Device List Web Page

The Known Modbus/RTU Device List page provides device specific status and statistics for each device on one or all ports.
Know Modbus/RTU Device List Page
evice ID Unit identifier associated with this device.
D
Status of device:
Active?
Tx Requests Number of Modbus messages transmitted to this device.
Rx Responses Number of Modbus responses received from this device.
Timeouts Number of response time-outs associated with this device.
Last Rsp Time The last response time from Modbus/RTU device.
Avg Rsp Time The average response time from Modbus/RTU device.
Min Rsp Time The minimum response time from Modbus/RTU device.
Max Rsp Time The maximum response time from Modbus/RTU device.
Invalid Responses Number of invalid responses received from this device.
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Embedded Diagnostic and Statistics Pages - 33
Ye s means that the last request received a valid response and did not time out.
No means that the last request timed out.

Serial Interface Communications Statistics Page

Serial Interface Communications Statistics Page
Where the following definitions apply:.
Counter Name Description
TX Byte Count (To Device) Number of bytes transmitted out the serial port.
TX Message Count Number of messages transmitted out the serial port.
RX Byte Count (From Device) Number of bytes received on the serial port.
RX Response Count Number of responses received on the serial port.
34 - Embedded Diagnostic and Statistics Pages DeviceMaster Modbus Server User Guide: 2000535 Rev. C
Serial Interface Communications Statistics Page
Counter Name Description
Parity Error Count
Framing Error Count
Number of parity errors received on the serial port. Typically occurs due to an incorrect parity setting.
Number of framing errors received on the serial port. Typically occurs due to an incorrect baud rate or stop bit setting.
Number of overrun errors received on the serial port.. Typically
Overrun Error Count
occurs to one of the following: incorrect flow control, incorrect baud rate, incorrect data size, or incorrect stop bit setting.
Number of invalid RTU device responses. These responses can be caused by the following:
Invalid RTU Device Responses
Message received after the timeout period. This may require increasing the Modbus/RTU Device Response Timeout.
Incorrect device ID in response message.
Incorrect function code in response message.
RTU Device Timeouts
The number of RTU device time-outs that occurred when there was no response for a Modbus message.
The status of the last device response:
Ye s – The last message received a valid response from a device
Last Device Active?
connected to the serial port.
No – The last message did not receive a valid response from a device connected to the serial port
The number of times a device went from the inactive state, (not
Device Transitions Inactive to Active
responding or no responses yet), to the active state (responding correctly).
In a system with all devices responding correctly, this number will typically equal the number of active devices.
The number of times a device went from the active state (responding
Device Transitions Active to Inactive
correctly) to the inactive state (not responding correctly).
This number is intended to help identify the number times devices respond intermittently.
Application Connection Statistics
TX Byte Count Number of bytes transmitted out of the TCP/IP connection(s).
TX Response Count (TO application)
Number of responses transmitted out of the TCP/IP connection(s).
The number of responses that were intended to be transmitted out
Dropped TX Responses
the TCP/IP connection(s) but could not be and were dropped. This typically occurs when one or more connections close unexpectedly.
RX Byte Count Number of bytes received on the TCP/IP connection(s).
RX Message Count (From Application)
Dropped RX Messages Due to Congestion
Number of messages received on the TCP/IP connection(s).
The number of messages that were dropped to the gateway being overly congested. This typically occurs when the application(s) send messages faster than the device(s) can respond.
The number of messages from the application(s) that were dropped
Dropped Invalid or Incomplete RX Messages
to:
Containing an invalid Modbus/RTU message format.
Containing an incomplete Modbus/RU message.
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Embedded Diagnostic and Statistics Pages - 35

Serial Interface Logs Page

Counter Name Description
Dropped RX Messages Due to In
valid CRCs
Number of messages from the application(s) that were dropped due to an invalid Modbus/RTU CRC.
TX Byte Count (To Device) Number of bytes transmitted out the serial port.
Serial Interface Logs Page
The following page displays the serial message transmitted and received during normal operation.
The format is as follows:
Pkt(N): ddd:hh:mm:ss.mss Rx/Tx:(data packet)
Where:
ddd Da
hh Hours sinc
mm Minutes since last
ss
mss Mi
(data) Mo
ys since last system restart
e last system restart
system restart
Seconds since last system restart
lliseconds since last system restart
dbus/RTU message data.
36 - Embedded Diagnostic and Statistics Pages DeviceMaster Modbus Server User Guide: 2000535 Rev. C

Troubleshooting and Technical Support

This section contains troubleshooting information for your DeviceMaster. You should review the following subsections before calling Technical Support because they will request that you perform many of the procedures or verifications before they will be able to help you diagnose a problem.
<hyperlink-CrossReference>Trouble
<hyperlink-CrossReference>General Troubleshooting on Page 38
<hyperlink-CrossReference>Daisy-Chaining DeviceMaster 2E/4-Port Units on Page 39
If you cannot diagnose the problem, you can contact <hyperlink­CrossReference>Technical Support on Page 40.

Troubleshooting Checklist

The following checklist may help you diagnose your problem:
Verify that you are using the correct types of cables on the correc and that all cables are connected securely.
Note: Most customer problems reported to Comtrol Technical Support are
Isolate the DeviceMaster from the network by connecting the device directly to a NIC in a host system.
shooting Checklist on Page 37
t connectors
eventually traced to cabling or network problems.
Model Connected to
1-Port Ethernet hub or NIC Standard 10/100 ETHERNET
1-Port Embedded Ethernet hub or NIC Standard RJ45 port (not labeled)
2-Port - 1E (All models)
2-Port - 2E (All dual Ethernet ports)
4-Port
Verify that the Ethernet hub and any other network devices between the system and the DeviceMaster are powered up and operating.
Reset the power on the DeviceMaster and watch the PWR or Status light activity.
PWR or Status LED Description
5 sec. off, 3 flashes, 5 sec. off, 3 flashes ... Redboot
5 sec. off, 4 flashes, 5 sec. off, 4 flashes ... SREC load failure.
5 quick flashes
10 sec. on, .1 sec. off, 10 sec. on .1 sec. off ...
Ethernet hub or NIC Standard 10/100
Ethernet hub or NIC Standard 10/100 - E1/E2
NIC Standard DOWN
Ethernet hub Standard UP
Ethernet
Cable
Connector Name
checksum failure.
The default application is starting up.
The default application is running.
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Troubleshooting and Technical Support - 37

General Troubleshooting

If the device has a power switch, turn the device’s power switch off and on, while watching the LED diagnostics.
If the DeviceMaster does not have a power switch, disconnect and reconnect the power cord.
Verify that the network IP address, subnet mask, and gateway is correct and appropriate for the network. If IP addressing is being used, the system should be able to ping the DeviceMaster.
Verify that the IP address programmed into the DeviceMaster matches the unique reserved IP configured address assigned by the system administrator.
If using DHCP, the host system needs to provide the subnet mask and gateway.
Reboot the system and the DeviceMaster.
If you have a spare DeviceMaster, try replacing the device.
General Troubleshooting
This table illustrates some general troubleshooting tips.
Note: Make sure that you have reviewed the <hyperlink-
CrossReference>Troubleshooting Checklist on Page 37.
General Condition Explanation/Action
Indicates that boot program has not downloaded to the unit.
1. Reboot the system.
PWR or Status LED flashing
2. Make sure that you have downloaded the most current firmware for your protocol:
fttp://ftp.comtrol.com/html/up_main.htm
Note: If the PWR or Status LED is still flashing,
contact Technical Support.
PWR or Status LED not lit
Cannot ping the device through Ethernet hub
Cannot ping or connect to the DeviceMaster
Indicates that power has not been applied or there is a hardware failure. Contact Technical Support.
Isolate the DeviceMaster from the network. Connect the device directly to the NIC in the host system (see Page 37).
The default IP address is often not accessible due to the subnet masking from another network unless 192.168 is used in the network.
In most cases, it will be necessary to program in an address that conforms to your network.
DeviceMaster continuously reboots when connected to some
Invalid IP information may also cause the switch or router to check for a gateway address. Lack of a
gateway address is a common cause. Ethernet switches or routers
.
38 - Troubleshooting and Technical Support DeviceMaster Modbus Server User Guide: 2000535 Rev. C

Daisy-Chaining DeviceMaster 2E/4-Port Units

The DeviceMaster 2E/4-port models with external power supplies follow the IEEE specifications for standard Ethernet topologies.
When using the UP an switch. When using the UP port only, it is a simple end node device.
The maximum number of daisy-chained DeviceMaster 2E/4 units, and the maximum distance between u determined by your own environment and the conformity of your network to these standards.
Comtrol has tested with seven DeviceMaster 2E/4 units daisy-chained together u
sing 10 foot CAT5 cables, but this is not the theoretical limit. You may experience a performance hit on the devices at the end of the chain, so it is recommended that you overload and test for performance in your environment. The OS and the application may also limit the total number of ports that may be installed.
Following are some quick guidelines and URLs of additional information. Please n
ote that standards and URLs do change.
Ethernet 10BASE-T Rules
- The maximum number of repeater hops is four.
- You can use Category 3 or 5 twisted-pair 10BASE-T cables.
- The maximum length of each cable is 100m (328ft).
Note: Category 3 or 5 twisted pair cables look the same as telephone cables
but they are not the same. The network will not work if telephone cables are used to connect the equipment.
Fast Ethernet 100BASE-TX rules
- The maximum number of repeater hops is two (for a Class II hub). A Class II hub can be connected directly to one other Class II Fast Ethernet hub. A Class I hub cannot be connected directly to another Fast Ethernet hub.
- You must use Category 5 twisted-pair 100BASE-TX cables.
- The maximum length of each twisted-pair cable is 100m (328ft).
- The total length of twisted-pair cabling (across directly connected hubs) must not exceed 205m (672ft).
Note: Category 5 twisted pair cables look the same as telephone cables but
they are not the same. The network will not work if telephone cables are used to connect the equipment.
IEEE 802.3 specification: A network using repeaters between communicating stations (PCs) is subject to the “5-4-3” rule of repeater placement on the network:
- Five segments connected on the network.
- Four repeaters.
- Three segments of the 5 segments can have stations connected. The other
two segments must be inter-repeater link segments with no stations connected.
See http://www.optronics.gr/Tutorials/ethernet.htm information.
Additional information may be found at http://compnetworking.about.com/
cs/ethernet1/ or by searching the web.
d DOWN ports, the DeviceMaster 2E/4 is classified as a
nits is based on the Ethernet standards and will be
Daisy-Chaining DeviceMaster 2E/4-Port Units
for more specific
DeviceMaster Modbus Server User Guide: 2000535 Rev. C Troubleshooting and Technical Support - 39

Technical Support

Technical Support
It contains troubleshooting procedures that you should perform before contacting Technical Support since they will request that you perform, some or all of the procedures before they will be able to help you diagnose your problem. If you need technical support, use one of the following methods.
Comtrol Contact Information
Downloads ftp://ftp.comtrol.com/html/up_modbus_server_main.htm
Web site http://www.comtrol.com
Phone 763.957.6000
40 - Troubleshooting and Technical Support DeviceMaster Modbus Server User Guide: 2000535 Rev. C
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