p
CDM-500
Satellite Modem
Installation and O
eration Manual
Part Number MN/CDM500.IOM Revision 1.3
Comtech EFData is an ISO 9001
Registered Company.
CDM-500
Satellite Modem
Installation and Operation Manual
Part Number MN/CDM500.IOM
Revision 1.3
July 10, 2000
Copyright © Comtech EFData, 2000. All rights reserved. Printed in the USA.
Comtech EFData, 2114 West 7th Street, Tempe, Arizona 85281 USA, (480) 333-2200, FAX: (480) 333-2161.
Customer Support
Contact the Comtech EFData Customer Support Department for:
• Product support or training
• Information on upgrading or returning a product
• Reporting comments or suggestions concerning manuals
A Customer Support representative may be reached at:
Comtech EFData
Attention: Customer Support Department
2114 West 7th Street
Tempe, Arizona 85281 USA
(480) 333-2200 (Main Comtech EFData Number)
(480) 333-4357 (Customer Support Desk)
(480) 333-2161 FAX
or, E-Mail can be sent to the Customer Support Department at:
service@comtechefdata.com
Contact us via the web at www.comtechefdata.com
1. To return a Comtech EFData product (in-warranty and out-of-warranty) for
repair or replacement:
2. Request a Return Material Authorization (RMA) number from the Comtech
EFData Customer Support Department.
3. Be prepared to supply the Customer Support representative with the model
number, serial number, and a description of the problem.
4. To ensure that the product is not damaged during shipping, pack the product in
its original shipping carton/packaging.
5. Ship the product back to Comtech EFData. (Shipping charges should be prepaid.)
For more information regarding the warranty policies, see Error! Reference source not
found., p. Error! Bookmark not defined..
.
Comtech EFData, 2114 West 7th Street, Tempe, Arizona 85281 USA, (480) 333-2200, FAX: (480) 333-2161.
Copyright © Comtech EFData, 2000. All rights reserved. Printed in the USA.
CDM-500 Satellite Modem Preface
Table of Contents
Customer Support........................................................................................................................................................ i
About this Manual ....................................................................................................................................................vii
Conventions and References...................................................................................................................................vii
Cautions and Warnings......................................................................................................................................vii
Metric Conversion..............................................................................................................................................vii
Reporting Comments or Suggestions Concerning this Manual..............................................................................vii
SAFETY NOTICES................................................................................................................................................. viii
Electrical Safety.....................................................................................................................................................viii
Fuses......................................................................................................................................................................viii
Environmental.......................................................................................................................................................... viii
Installation..................................................................................................................................................................ix
Telecommunications Terminal Equipment Directive............................................................................................. ix
EMC (Electromagnetic Compatibility).................................................................................................................... ix
Warranty Policy.......................................................................................................................................................... x
Limitations of Warranty ........................................................................................................................................... x
Exclusive Remedies.................................................................................................................................................. x
CHAPTER 1.
INTRODUCTION.................................................................................1–1
1.0 Introduction.................................................................................................................................................. 1–1
CHAPTER 2.
2.0 Unpacking..................................................................................................................................................... 2–1
2.1 Mounting.......................................................................................................................................................2–1
Rev. 1.3 i
INSTALLATION..................................................................................2–1
Preface CDM-500 Satellite Modem
2.2 Configuration................................................................................................................................................ 2–2
2.3 Select Internal IF Loop................................................................................................................................ 2–2
2.4 Connect External Cables ............................................................................................................................. 2–2
CHAPTER 3.
3.0 Functional Description................................................................................................................................. 3–1
CHAPTER 4.
4.1 Front Panel ................................................................................................................................................... 4–1
4.2 Rear Panel..................................................................................................................................................... 4–3
CHAPTER 5.
5.1 Connector Pinouts........................................................................................................................................ 5–1
5.1.1 Data Connector - 25 Pin ‘D’ Type Female..............................................................................................5–1
5.2 Alarms Connector - 15 Pin ‘D’ Type Male................................................................................................. 5–2
FUNCTION..........................................................................................3–1
PHYSICAL DESCRIPTION.................................................................4–1
CONNECTOR PINOUTS.....................................................................5–1
5.3 Remote Control Connector - 9 Pin ‘D’ Type Male................................................................................. ... 5–3
5.4 Auxiliary Serial Connector - He1402 3 Pin Header .................................................................................. 5–3
CHAPTER 6.
6.1 Description.................................................................................................................................................... 6–1
6.2 Menu Trees................................................................................................................................................... 6–3
6.3 OPENING SCREEN.................................................................................................................................... 6–4
6.4 SELECT........................................................................................................................................................ 6–4
6.5 CONFIG: ...................................................................................................................................................... 6–5
6.5.1 (CONFIG) TX (Transmit)...................................................................................................................... 6–5
6.5.2 (CONFIG, TX) MOD (Modulation)....................................................................................................... 6–6
6.5.3 (CONFIG, TX) FREQ (Frequency)........................................................................................................ 6–6
6.5.4 (CONFIG, TX) DATA (Data Rate)........................................................................................................ 6–6
6.5.5 (CONFIG, TX) FEC (Forward Error Correction)...................................................................................6–6
6.5.6 (CONFIG, TX) ON/OFF........................................................................................................................ 6–6
6.5.7 (CONFIG, TX) PWR (Power)................................................................................................................ 6–7
6.5.8 (CONFIG, TX) SCRAM (Scrambling) .................................................................................................. 6–7
6.5.9 (CONFIG, TX) CLK (Clocking)............................................................................................................6–7
6.5.10 (CONFIG, TX) TSI (Transmit Spectral Invert) ................................................................................6–7
6.5.11 (CONFIG) RX (Receive)................................................................................................................... 6–8
6.5.12 (CONFIG, RX) MOD (Modulation).................................................................................................. 6–8
6.5.13 (CONFIG, RX) FRQ (Frequency)......................................................................................................6–8
FRONT PANEL OPERATION.............................................................6–1
ii Rev. 1.3
CDM-500 Satellite Modem Preface
6.5.14 (CONFIG, RX) DATA (Data Rate)................................................................................................... 6–8
6.5.15 (CONFIG, RX) FEC (Forward Error Correction).............................................................................. 6–8
6.5.16 (CONFIG, RX) ACQ (Acquisition sweep range) .............................................................................. 6–9
6.5.17 (CONFIG, RX) DESCRAM (Descrambler).......................................................................................6–9
6.5.18 (CONFIG, RX) CLK (Clocking).........................................................................................................6–9
6.5.19 (CONFIG, RX) BUF (Buffer size).................................................................................................... 6–10
6.5.20 (CONFIG, RX) RSI (Receive spectral inversion) ............................................................................. 6–10
6.5.21 (CONFIG, RX) Eb/No (Eb/No Alarm).............................................................................................6–10
6.5.22 (CONFIG) FRAME (Framing Mode)...............................................................................................6–10
6.5.23 (CONFIG, FRAME) TRANSPARENT............................................................................................6–10
6.5.24 (CONFIG, FRAME) FRAMED........................................................................................................6–11
6.5.25 (CONFIG, FRAME, FRAMED) EDMAC-ON.................................................................................6–11
6.5.26 (CONFIG, FRAME, FRAMED, ON) EDMAC MASTER............................................................... 6–11
6.5.27 (CONFIG, FRAME, FRAMED, ON) EDMAC SLAVE..................................................................6–12
6.5.28 (CONFIG) INTFC (Interface)...........................................................................................................6–12
6.5.29 (CONFIG) REMCONT (Remote control).........................................................................................6–12
6.5.30 (CONFIG, LOCAL) .......................................................................................................................... 6–12
6.5.31 (CONFIG, REMOTE).......................................................................................................................6–12
6.5.32 (CONFIG, REMOTE, BAUD)..........................................................................................................6–13
6.5.33 (CONFIG, REMOTE, INTFC) ......................................................................................................... 6–13
6.5.34 (CONFIG, REM, INTFC, ADDR) RS232 BUS ADDRESS...........................................................6–13
6.5.35 (CONFIG, REM, INTFC, ADDR) RS485 BUS ADDRESS:.......................................................... 6–13
6.5.36 (CONFIG) MASK (Alarm mask).....................................................................................................6–13
6.5.37 (CONFIG, MASK) AGC ................................................................................................................. 6–14
6.5.38 (CONFIG, MASK) Eb/No ................................................................................................................ 6–14
6.5.39 (CONFIG, MASK) RX-AIS .............................................................................................................6–14
6.5.40 (CONFIG, MASK) BUF-SLIP (Buffer slip)..................................................................................... 6–14
6.5.41 (CONFIG, MASK) TX-AIS.............................................................................................................. 6–15
6.5.42 (CONFIG) IMPED (IF impedance) ..................................................................................................6–15
6.6 TEST ........................................................................................................................................................... 6–16
6.7 INFO (Information)................................................................................................................................... 6–17
6.7.1 (INFO) ID (Circuit ID).......................................................................................................................... 6–17
6.7.2 (INFO) TX (Transmit information)....................................................................................................... 6–17
6.7.3 (INFO) RX (Receive information)........................................................................................................ 6–17
6.7.4 (INFO) BUFF (Buffer information)...................................................................................................... 6–18
6.7.5 (INFO) EDMAC (Framing and EDMAC information)......................................................................... 6–18
6.7.6 (INFO) REMCONT (Remote Control information).............................................................................. 6–18
6.7.7 (INFO) MASK (Alarm mask information)............................................................................................ 6–18
6.7.8 (INFO) MISC (Miscellaneous information).......................................................................................... 6–19
6.8 MONIT (Monitor)...................................................................................................................................... 6–20
6.8.1 (MONIT) ALARMS.............................................................................................................................. 6–20
6.8.2 (MON, ALARMS) UNIT (Unit alarms)................................................................................................ 6–20
6.8.3 (MON, ALARMS) RECEIVE (Receive alarms)................................................................................... 6–20
6.8.4 (MON, ALARMS) TRANSMIT (Transmit alarms).............................................................................. 6–20
6.8.5 (MONIT) STORED EVENTS............................................................................................................... 6–21
6.8.6 (MON, EVENTS) VIEW ......................................................................................................................6–21
6.8.7 (MONIT) RX-PARAMS (Receive Parameters).................................................................................... 6–22
6.9 STORE/LD (Store/Load)........................................................................................................................... 6–23
6.9.1 (STORE/LD) STORE............................................................................................................................ 6–23
6.9.2 (STO/LD) LOAD .................................................................................................................................. 6–23
Rev. 1.3 iii
Preface CDM-500 Satellite Modem
6.10 UTIL (Utility) ............................................................................................................................................. 6–25
6.10.1 (UTIL) SET-RTC (Set real-time clock)............................................................................................ 6–25
6.10.2 (UTIL) DISPLAY (Display brightness)............................................................................................ 6–25
6.10.3 (UTIL) MAN-1:1 (Manual 1:1 switchover)......................................................................................6–25
6.10.4 (UTIL) RECENTER-BUF (re-center buffer).................................................................................... 6–25
6.10.5 (UTIL) ID (Circuit ID)...................................................................................................................... 6–26
CHAPTER 7.
7.1 Transmit Clocking........................................................................................................................................ 7–1
7.1.1 Internal Clock.......................................................................................................................................... 7–1
7.1.2 External Clock......................................................................................................................................... 7–1
7.1.3 Loop-Timed............................................................................................................................................. 7–2
7.2 Receive Clocking .......................................................................................................................................... 7–2
7.2.1 Buffer Disabled ....................................................................................................................................... 7–2
7.2.2 Buffer Enabled, Rx=Tx........................................................................................................................... 7–2
7.2.3 Buffer Enabled, Rx<>Tx......................................................................................................................... 7–2
7.3 X.21 Notes..................................................................................................................................................... 7–2
CHAPTER 8.
8.1 Theory Of Operation ...................................................................................................................................8–1
CLOCKING .........................................................................................7–1
EDMAC CHANNEL.............................................................................8–1
8.2 M&C Connection ......................................................................................................................................... 8–2
8.3 Setup Summary............................................................................................................................................ 8–3
APPENDIX A.
A.1 Modulator.....................................................................................................................................................A–1
A.2 Demodulator.................................................................................................................................................A–2
A.3 Data Interfaces..............................................................................................................................................A–3
A.4 Miscellaneous................................................................................................................................................A–3
A.5 Approvals......................................................................................................................................................A–3
APPENDIX B.
B.1 Introduction..................................................................................................................................................B–1
B.2 EIA-485.........................................................................................................................................................B–1
B.3 EIA-232.........................................................................................................................................................B–2
SUMMARY OF SPECIFICATIONS.................................................... A–1
REMOTE CONTROL..........................................................................B–1
B.4 Basic Protocol...............................................................................................................................................B–2
iv Rev. 1.3
CDM-500 Satellite Modem Preface
B.5 Packet Structure...........................................................................................................................................B–3
B.5.1
B.5.2
B.5.3
B.5.4
B.5.5
B.5.6
Start Of Packet .................................................................................................................................... B–3
Address................................................................................................................................................B–3
Instruction Code..................................................................................................................................B–4
Instruction Code Qualifier...................................................................................................................B–4
Message Arguments............................................................................................................................B–5
End Of Packet .....................................................................................................................................B–5
Rev. 1.3 v
Preface CDM-500 Satellite Modem
Figures
FIGURE 1-1 CDM500 PHOTO...............................................................................................................................1–1
FIGURE 4-1 FRONT AND BACK PANELS......................................................................................................... 4–2
FIGURE 6-1 PRINCIPLE MENU TREE................................................................................................................ 6–3
FIGURE A-1 BER VITERBI DECODING............................................................................................................ A–4
Tables
TABLE 4-1- FRONT PANEL LED INDICATORS ................................................................................................ 4–2
TABLE 5-1 25 PIN ‘D’ TYPE FEMALE................................................................................................................5–1
TABLE 5-2 ALARMS CONNECTOR.....................................................................................................................5–2
TABLE 5-3 REMOTE CONTROL CONNECTOR................................................................................................. 5–2
TABLE 5-4 AUXILIARY SERIAL CONNECTOR................................................................................................ 5–3
vi Rev. 1.3
CDM-500 Satellite Modem Preface
About this Manual
This manual provides installation and operation information for the Comtech EFData
CDM-500 satellite modem. This is a technical document intended for earth station
engineers, technicians, and operators responsible for the operation and maintenance of
the CDM-500.
Conventions and References
Cautions and Warnings
CAUTION indicates a hazardous situation that, if not avoided, may result in
minor or moderate injury. CAUTION may also be used to indicate other
CAUTION
WARNING
unsafe practices or risks of property damage.
WARNING indicates a potentially hazardous situation that, if not avoided,
could result in death or serious injury.
Metric Conversion
Metric conversion information is located on the inside back cover of this manual. This
information is provided to assist the operator in cross-referencing English to Metric
conversions.
Reporting Comments or Suggestions Concerning this Manual
Comments and suggestions regarding the content and design of this manual will be
appreciated. To submit comments, please contact the Comtech EFData Customer Support
Department.
Rev. 1.3 vii
Preface CDM-500 Satellite Modem
SAFETY NOTICES
Electrical Safety
The CDM-500 VSAT Modem has been shown to comply with the following safety
standard:
EN 60950: Safety of Information Technology Equipment, including electrical
business machines
The equipment is rated for operation over the range 100 - 240 volts AC. It has a
maximum power consumption of 25 watts, and draws a maximum of 250 mA.
The user should observe the following instructions:
Fuses
The CDM-500 is fitted with two fuses - one each for line and neutral connections. These
are contained within the body of the IEC power inlet connector, behind a small plastic
flap.
For 230 volt AC operation, use T0.5A, 20mm fuses.
For 115 volt AC operation, use T1A fuses, 20mm fuses.
FOR CONTINUED OPERATOR SAFETY, ALWAYS REPLACE THE FUSES WITH
THE CORRECT TYPE AND RATING.
IMPORTANT INFORMATION - PLEASE READ
BEFORE INSTALLATION AND USE
Environmental
The CDM-500 must not be operated in an environment where the unit is:
• Exposed to extremes of temperature outside the ambient range 0 to 50 C, 0
precipitation, condensation, or humid atmospheres above 95% RH,
• Altitudes (un-pressurised) greater than 2000 metres, excessive dust or vibration,
flammable gases, corrosive or explosive atmospheres.
• Operation in vehicles or other transportable installations which are equipped to
provide a stable environment is permitted. If such vehicles do not provide a stable
environment, safety of the equipment to EN60950 may not be guaranteed.
viii Rev. 1.3
CDM-500 Satellite Modem Preface
Installation
The installation and connection to the line supply must be made in compliance to local or
national wiring codes and regulations.
The CDM-500 is designed for connection to a power system that has separate earth, line
and neutral conductors. The equipment is not designed for connection to power system
which has no direct connection to earth.
The CDM-500 is shipped with a line inlet cable suitable for use in the country of
operation. If it is necessary to replace this cable, ensure the replacement has an equiv alent
specification. Examples of acceptable ratings for the cable include HAR, BASEC and
HOXXX-X.
Examples of acceptable connector ratings include VDE, NF-USE, UL, CSA, OVE,
CEBEC, NEMKO, DEMKO, BS1636A, BSI, SETI, IMQ, KEMA-KEUR and SEV.
Telecommunications Terminal Equipment Directive
In accordance with the Telecommunications Terminal Equipment Directive 91/263/EEC,
this equipment should not be directly connected to the Public Telecommunications
Network.
EMC (Electromagnetic Compatibility)
The CDM-500 VSAT Modem has been demonstrated, by independent testing, to comply
with the following standards:
Emissions: EN 55022 Class B - Limits and methods of measurement of radio
interference characteristics of Information Technology Equipment.
FCC Part 15 Class B
Immunity: EN 50082 Part 1 - Generic immunity standard, Part 1: Domestic,
commercial and light industrial environment.
In order that the Modem continues to comply with these standards, observe the following
instructions:
• Connections to the transmit and receive IF ports (BNC female connectors) should be
made using a good quality coaxial cable – for example RG58/U (50 ohm) or RG59/U
(75 ohm).
• All 'D' type connectors attached to the rear panel must have back-shells which provide
continuous metallic shielding. Cable with a continuous outer shield (either foil or
braid, or both) must be used, and the shield must be bonded to the back-shell.
• The equipment must be operated with its cover on at all times. If it becomes necessary
to remove the cover, the user should ensure that the cover is correctly re-fitted before
normal operation commences.
Rev. 1.3 ix
Preface CDM-500 Satellite Modem
Warranty Policy
This Comtech EFData product is warranted against defects in material and workmanship
for a period of two years from the date of shipment. During the warranty period, Comtech
EFData will, at its option, repair or replace products that prove to be defective.
For equipment under warranty, the customer is responsible for freight to Comtech
EFData and all related custom, taxes, tariffs, insurance, etc. Comtech EFData is
responsible for the freight charges only for return of the equipment from the factory to
the customer. Comtech EFData will return the equipment by the same method (i.e., Air,
Express, Surface) as the equipment was sent to Comtech EFData.
Limitations of Warranty
The foregoing warranty shall not apply to defects resulting from improper installation or
maintenance, abuse, unauthorized modification, or operation outside of environmental
specifications for the product, or, for damages that occur due to improper repackaging of
equipment for return to Comtech EFData.
No other warranty is expressed or implied. Comtech EFData specifically disclaims the
implied warranties of merchantability and fitness for particular purpose.
Exclusive Remedies
The remedies provided herein are the buyer's sole and exclusive remedies. Comtech
EFData shall not be liable for any direct, indirect, special, incidental, or consequential
damages, whether based on contract, tort, or any other legal theory.
Disclaimer
Comtech EFData has reviewed this manual thoroughly in order that it will be an easy-touse guide to your equipment. All statements, technical information, and
recommendations in this manual and in any guides or related documents are believed
reliable, but the accuracy and completeness thereof are not guaranteed or warranted, and
they are not intended to be, nor should they be understood to be, representations or
warranties concerning the products described. Further, Comtech EFData reserves the
right to make chang es in the specifications of the products described in this m anual at any
time without notice and without obligation to notify any person of such changes.
If you have any questions regarding your equipment or the information in this manual,
please contact the Comtech EFData Customer Support Department.
x Rev. 1.3
1.0 Introduction
The CDM-500 (Figure 1-1) is a very low-cost C losed Netw ork Satellite Modem, intended
for VSAT applications. It offers variable data rates from 2.4 to 512kbps, in BPSK and
QPSK modes. It is extremely compact, being 1U high and 12 inches deep, and consumes
only 18 watts. It has a front panel VFD display and keypad for local configuration and
control, although it can be fully remote-controlled. For 1:1 applications the CDM-500 is
supported by a low-cost external switch, the CRS-100. For Hub applications, the CDM500 is supported by a low-cost 1:N switch, the CRS-200. Its fast acquisition time makes
it attractive for both demand-assigned and fixed-assigned SCPC applications.
Chapter 1.
INTRODUCTION
1
Figure 1-1. CDM-550 Satellite Modem
Rev. 1.3 1–1
Introduction CDM-500 Closed Network Satellite Modem
The CDM-500 includes, as standard, a universal data interface which eliminates the need
to exchange interface cards for different applications. The interfaces offered include
RS422 (EIA530) DCE, V.35 DCE, synchronous RS232 DCE, and X.21 DTE and DCE.
The internal software is both powerful and flexible, and permits the user to store, and
then retrieve, up to 10 different modem configurations. The unit includes many test
modes and loopbacks for rapid verification of the correct functioning of the unit. Of
particular note is the IF loopback, which permits the user to perform a quick diagnostic
test without having to disturb external cabling. During the loopback, all of the receive
configuration parameters are temporarily changed to match those of the transmit side.
When normal operation is again selected, all of the previous values are restored.
A perennial problem is that of the IF port impedance. Whilst many users select the
universal standard of 50 ohms, there are many users who are still using 75 ohms. In the
past this has presented difficulties for the manufacturer, who has traditionally had to offer
both options. The CDM-500 eliminates this problem, by offering both impedances in the
same unit. The user simply selects from the front panel which impedance he wishes to
use.
In order to facilitate network management, the CDM-500 incorporates
EDMA
C, an
acronym for Embedded Distant-end Monitor And Control. In this mode, an additional 5%
overhead is combined with the traffic data, which permits M&C information to be added
(transparently to the user), allowing access to the distant-end modem.
This mode does not require any additional cabling at either the local or distant-end
Modems - access to EDMAC is via the standard M&C control port. Full monitor and
control is possible, and importantly, the on/off status of the carrier at the distant-end
carrier can be controlled.
The CDM-500 has been designed as a companion product for the Comtech EFData line
of RF Transceivers. As such, the Modem incorporates an FSK serial link which can be
activated on the Receive IF port, for the purpose of communicating with a Transceiver, if
connected. In this manner, a user may monitor, configure, and control the Transceiver,
using the front panel display and keypad of the Modem. The EDMAC channel may also
be used to convey M&C data to a Transceiver at the distant end of a satellite link, if it is
connected to a CDM-500.
1–2 Rev. 1.3
2.0 Unpacking
Inspect shipping containers for damage. If shipping containers are damaged, they should
be kept until the contents of the shipment have been carefully inspected and checked for
normal operation.
Remove the packing list from the outside of the shipping carton. Open the carton and
remove the contents, checking the contents against the packing list. Verify completeness
of the shipment and that the unit functions correctly. If damage is evident, contact the
carrier and Comtech immediately and submit a damage report. Be sure to keep all
shipping materials for the carrier's inspection.
If the unit needs to be returned to Comtech EFData, please use the original shipping
container.
Chapter 2.
INSTALLATION
2
2.1 Mounting
If the CDM-500 is to be mounted in a rack, ensure that there is adequate clearance for
ventilation. The CDM-500 does not include a cooling fan, so care must be taken that too
many units are not mounted on top of each other. The limit is four units, and then a blank
1U panel must be inserted to allow sufficient airflow around the units. In rack systems
where there is high heat dissipation, forced air cooling must be provided by top or bottom
mounted fans or blowers. Under no circumstance should the highest internal rack
temperature be allowed to exceed 50 C.
Rev. 1.3 2–1
Installation CDM-500 Closed Network Satellite Modem
Note that the CDM-500 is very light - under 7 lbs (3.2 kgs), and very short – 12 ins (305
mm). For this reason, it has not been designed to have rack slides mounted to the side of
the chassis. However, Comtech recommends that some method of support within the rack
should be employed, such a rack shelves. If the user is any doubt, please consult the
factory.
2.2 Configuration
There are no internal jumpers to configure, no interface cards to install, and no other
options to install. All configuration is carried out entirely in software. The unit should
first be configured locally, using the front panel keypad and display. The unit will ship
with a default 64 kbps, QPSK, Rate 1/2 configuration. Please refer to the ‘FRONT
PANEL OPERATION’ section for details on how to fully configure the unit for the
desired operating parameters.
The auto-sensing AC power supply does not require any adjustments. Simply plug in the
supplied line cord, and turn on the switch on the rear panel.
2.3 Select Internal IF Loop
Correct operation of the unit may be verified rapidly, without the need for
externally connected equipment. From the top level menu, select TEST, then IF
LOOP (refer to the ‘FRONT PANEL OPERATION’ section) The demod should
synchronize, and the green RECEIVE TRAFFIC LED should illuminate. If the unit
does not pass this test, call the factory for assistance.
2.4 Connect External Cables
Having verified correct operation in IF loop, the user should now enter his desired
configuration, and proceed to connect all external cables. If difficulties are experienced,
please call the factory for assistance.
Please note that the modulator gives an output power level in the range 0 to –20 dBm,
and the demodulator expects to see a signal in the range -30 to -60 dBm.
2–2 Rev. 1.3
3
3.0 Functional Description
The CDM-500 has two fundamentally different types of interface - IF and data. The data
interface is a bi-directional path which connects with the customer’s equipment (assumed
to be the DTE) and the modem (assumed to be the DCE). The IF interface provides a bidirectional link with the satellite via the uplink and downlink equipment.
Transmit data is received by the terrestrial interface where line receivers convert the
clock and data signals to CMOS levels for further processing. A small FIFO follows the
terrestrial interface to facilitate the various clocking and framing options. If framing is
enabled, the transmit clock and data output from the FIFO pass through the framer, where
the EDMAC data is added to the main data. Otherwise, the clock and data are passed
directly to the Forward Error Correction encoder. In the FEC encoder, the data is
differentially encoded, scrambled, and then convolutionally encoded. Following the
encoder, the data is fed to the transmit digital filters, which perform spectral shaping on
the data signals. The resultant I and Q signals are then fed to the QPSK/BPSK modulator.
The carrier is generated by a frequency synthesizer, and the I and Q signals directly
modulate this carrier to produce an IF output signal.
The received IF signal is first translated to a fixed IF frequency, using a frequency
synthesizer. An AGC circuit maintains the composite level within the IF bandwidth
constant over a limited range. Following this, the signal is sampled by a high-speed
(flash) A/D converter. All processing beyond this conversion is purely digital. The signal
is translated down to near zero frequency by a complex mix, and then is processed by a
digital Costas Loop, which performs the functions of Nyquist filtering, carrier recovery,
and bit-timing recovery. The resultant demodulated signal is fed, in soft decision form, to
the Viterbi (FEC) decoder. After decoding, the recovered clock and data pass to the deframer (if EDMAC is enabled) where the overhead information is removed.
Chapter 3.
FUNCTION
Rev. 1.3 3–1
Function CDM-500 Closed Network Satellite Modem
Following this, the data passes to the Plesiochronous/Doppler buffer, which has a
programmable size, or may be bypassed. From here, the receive clock and data signals
are routed to the terrestrial interface, and are passed to the externally connected DTE
equipment.
3–2 Rev. 1.3
PHYSICAL DESCRIPTION
The CDM-500 is constructed as a 1U high rack-mounting chassis, which can be
free-standing, if desired. It is provided with rack-handles at the front to facilitate
its removal from, and placement into a rack. Figure 1 shows the front and rear
panels of the modem.
4.1 Front Panel
On the front panel of the unit is the Vacuum Fluorescent Display (VFD), keypad, and
eight LED indicators. The user enters data via the keypad, and messages are displayed on
the VFD. The LEDs indicate, in a summary fashion, the status of the unit.
The Vacuum Fluorescent Display (VFD) is an active display showing 2 lines, each of 24
characters. It produces a pleasing blue light, the brightness of which can be controlled by
the user. It has greatly superior viewing characteristics compared to a Liquid Crystal
Display (LCD), and does not suffer problems of viewing angle or contrast.
The keypad comprises six individual keyswitches, mounted directly behind a fully sealed
membrane overlay. They have a positive ‘click’ action, which provides the user with
tactile feedback. These six switches are identified as UP ARROW, DOWN ARROW,
RIGHT ARROW, LEFT ARROW, ENTER and CLEAR. The functions of these keys are
described in the ‘Front Panel Operation’ section.
There are 8 LED indicators. The functions of these indicators are shown in the Table 1
below:
Chapter 4.
4
Rev. 1.3 4–1
Physical Description CDM-500 Closed Network Satellite Modem
Table 4-1- Front Panel Led Indicators
LED Color Condition
Red A Unit Fault exists (Example: PSU fault)
Unit Status
Transmit
Traffic
Receive
Traffic
On line
Stored
Event
Remote
EDMAC
Mode
Test Mode
Orange No Unit Faults, but a Traffic Fault exists
Green No Unit Faults, or Traffic Faults
Green No Tx Traffic Faults
Off A Tx Traffic fault exists
OR the Tx Carrier is in OFF state
Green No Rx Traffic Faults (demod and Viterbi decoder are
locked, everything is OK)
Off An Rx Traffic fault exists (the demod may still be OK)
Green The Unit is On Line, and carrying traffic
Off The Unit is Off Line (standby) - forced by externally
connected 1:1 or 1:N redundancy system
Orange There is a Stored Event in the log, which can be viewed
from the front panel, or retrieved via the remote control
interface
Off There are no Stored Events
Orange The Unit is in Remote Mode - local monitoring is
possible, but no local control
Off The Unit is in Local Mode - remote monitoring is
possible, but no remote control
Orange Framing on, EDMAC on, and unit defined as Slave
Off Either no EDMAC, EDMAC Master, or Transparent
mode is selected
Orange A Test Mode is selected (Example: IF Loopback)
Off There is no Test Mode currently selected
Figure 4-1 Front and Back panels
4–2 Rev. 1.3
CDM-500 Closed Network Satellite Modem Physical Description
4.2 Rear Panel
All external cables are attached to connectors on the rear panel of the CDM-500. These
comprise the IEC line input connector, the Receive and Transmit IF connectors, the Data
connector, Alarms connector, Remote Control connector, and Auxiliary Serial connector.
The IEC line input connector contains the ON/OFF switch for the unit. It is also fitted
with two fuses - one each for line and neutral connections (or L1, L2, where appropriate).
These are contained within the body of the connector, behind a small plastic flap.
For 230 volt AC operation, use T0.5A, (slow-blow) 20mm fuses.
For 115 volt AC operation, use T1A fuses, (slow-blow) 20mm fuses.
FOR CONTINUED OPERATOR SAFETY, ALWAYS REPLACE THE FUSES WITH
THE CORRECT TYPE AND RATING.
The IF port connectors are both a 50 ohm BNC female type. 75 ohm cable connectors
(male) will have no problem mating with this 50 ohm type. The Data connector is a 25
pin ‘D’ type female (DB25-F). This connector conforms to the EIA 530 pinout, which
allows for connection of different electrical standards, including EIA-422, V.35, and
EIA-232. Please note that it is the responsibility of the user to provide the appropriate
cables to connect to this EIA 530 connector. A shielded 25 pin ‘D’ type provides a very
solid solution to EMC problems, unlike the sometimes used V.35 Winchester connector.
The pinout for the EIA 530 connector is provided in the next section.
Note that currently selected interface type is indicated by a small orange LED which is
located immediately above the connector. This provides aa easy visual indication to
anyone mating a connector at the rear of the unit.
The Alarms connector is a 15 pin 'D' type male (DB15-M). This provides the user with
access to the Form-C relay contacts which indicate the fault status of the unit. These are
typically connected to an external fault monitoring system, often found in satellite earth
stations. In addition, the receive I and Q demodulator samples are provided on this
connector. Connecting these signals to an oscilloscope in X,Y mode will provide the
receive signal constellation diagram, which is a useful diagnostic aid. A pin is also
provided which can mute the transmit carrier. This requires that the pin be shorted to
ground, or a TTL ‘low’, or an EIA-232 ‘high’ signal be applied. The pinout details for
this connector are provided in the next section.
The Remote Control connector is a 9 pin 'D' type female (DB9-M). Access is provided to
remote control ports of the modem, both EIA-232 and EIA-485. The pinout details for
this connector are provided in the next section.
The Auxiliary Serial connector is an HE1402 3 pin header. A suitable mate for this
connector is AMP part number 281838-3, with three crimp pins, AMP part number
182734-2, also required. This is an additional EIA-232 serial port, which is only used
when the modem is part of a 1:1 pair, at the distant-end of a link, and when both units are
defined as EDMAC slaves. The pinout details for this connector are provided in the next
section.
Rev. 1.3 4–3
Physical Description CDM-500 Closed Network Satellite Modem
This page is intentionally blank.
4–4 Rev. 1.3
CONNECTOR PINOUTS
5.1 Connector Pinouts
Chapter 5.
5
5.1.1 Data Connector
Pin Generic Signal
description
1 Shield - Shield FG AA 101
2 Transmit Data A DTE to Modem SD A SD A BA 103
3 Receive Data A Modem to DTE RD A RD A BB 104
7 Signal Ground - SG SG AB 102
8 Receiver Ready A Modem to DTE RR A RLSD* CF 109
9 Receive Clock B Mod em to DTE RT B SCR B - 115
10 Receiver Ready B Modem to DTE RR B - - 109
11 Transmit Clock B DTE to Modem TT B SCTE B - 113
12 Internal Transmit Clock B Modem to DTE ST B SCT B - 114
14 Transmit Data B DTE to Modem SD B SD B - 103
15 Internal Transmit Clock A Modem to DTE ST A SCT A DB 114
16 Receive Data B Modem to DTE RD B RD B - 104
17 Receive Cl ock A Modem to DTE RT A SCR A DD 115
23 External Carrier Off
(RS232 ‘1' or TTL ‘low’ )
24 Transmit Clock A DTE to Modem TT A SCTE A DA 113
NOTES:
Receiver ready is an RS232-level control signal on a V.35 interface
•
-
25 Pin ‘D’ Type Female
Table 5-1 25 Pin ‘D’ Type Female
Direction RS422/ EIA
DTE to Modem - - - -
530
V.35 RS232 Circuit
No
Rev. 1.3 5–1
Connector Pinouts CDM-500 Closed Network Satellite Modem
• DO NOT connect signals to pins which are not shown - these pins are reserved for
use by the redundancy system
‘B’ signal lines are not used for RS232 applications
•
For X.21 operation, use the RS422 pins, but ignore Receive Clock if the Modem is
•
DTE, and ignore Transmit clocks if the Modem is DCE
5.2 Alarms Connector - 15 Pin ‘D’ Type Male
Table 5-2 Alarms Connector
Pin Description
1 Ground
5 Unit Fault Relay - Normally Open
12 Unit Fault Relay - Normally Closed
4 Unit Fault Relay - Common
8 Receive Traffic Relay - Normally Open
15 Receive Traffic Relay - Normally Closed
7 Receive Traffic Relay - Common
14 Transmit Traffic Relay - Normally Open
6 Transmit Traffic Relay - Normally Closed
13 Transmit Traffic Relay - Common
11 Receive I sample (for constellation display)
3 Receive Q sample (for constellation display)
2 Receive AGC voltage
9 External Carrier Off input
10 ---- No Connection ----
Note:
‘Normally Open’ refers to the NON-FAIL state
5–2 Rev. 1.3
CDM-500 Closed Network Satellite Modem Connector Pinouts
5.3 Remote Control Connector - 9 Pin ‘D’ Type Male
Table 5-3 Remote Control Connector
Pin Description
1 Ground
5 Ground
9 RS485 Transmit Data A
8 RS485 Transmit Data B
7 RS485 Receive Data A
6 RS485 Receive Data B
2 RS232 Transmit Data
3 RS232 Receive Data
4 Reserved - do not connect to this pin
5.4 Auxiliary Serial Connector - He1402 3 Pin Header
Table 5-4 Auxiliary Serial Connector
Pin Description
1 RS232 Transmit Data
2 Ground
3 RS232 Receive Data
Rev. 1.3 5–3
Connector Pinouts CDM-500 Closed Network Satellite Modem
This page has been intentionally left blank.
5–4 Rev. 1.3
FRONT PANEL OPERATION
6.1 Description
The user can fully control and monitor the operation of the CDM-500 from the front
panel, using the keypad and display. Nested menus are used, which display all available
options, and prompt the user to carry out a required action.
The display has two lines each of 24 characters. On most menu screens, the user will
observe a flashing
indicates the currently selected item, digit, or field. Where this solid block cursor would
obscure the item being edited (for example, a numeric field) the cursor will automatically
change to an underline cursor.
If the user were to display the same screen for weeks at a time, the display could become
‘burnt’ with this image. To prevent this, the unit has a ‘screen saver’ feature which will
activate after 1 hour. The top line of the display will show the Cicuit ID (which can be
entered by the user) and the bottom line will show the circuit Eb/No value (if the demod
is locked) followed by ‘Press any key....
the screen, then wraps around. Pressing any key will restore the previous screen.
The keypad has six keys, the functions of which are described below:
solid block curso
Chapter 6.
6
r, which blinks at a once-per-second rate. This
The message moves from right to left across
’.
Rev. 1.3 6–1
Front Panel Operation CDM-500 Closed Network Satellite Modem
RIGHT ARROW Moves the cursor to the right, when it is displayed
LEFT ARROW Moves the cursor to the left, when it is displayed
UP ARROW Used for editing the value at the current cursor position, if
appropriate. If this is a numeric field, this will increment the value.
DOWN ARROW Used for editing the value at the current cursor position, if
appropriate. If this is a numeric field, this will decrement the value.
ENTER (ENT) Used to accept an edited entry. Most menus prompt the user to
press this key, by displaying the text (PRESS ENTER), (ENTER) or
(ENT). This results in the entry being accepted, and the user is then
returned to the previous menu
CLEAR (CLR) Used to escape from the current operation and return to the previous
menu
IMPORTANT NOTE: The keypad has an auto-repeat feature. If a key is held down for
more than 1 second, the key action will repeat, automatically, at the
rate of 15 keystrokes per second. This is particularly useful when
editing numeric fields, with many digits, such as frequency or data
rate.
6–2 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.2 Menu Trees
Figure 2 shows the menu structure of the CDM-500.
Figure 6-1 Principle Menu Tree
Rev. 1.3 6–3
Front Panel Operation CDM-500 Closed Network Satellite Modem
6.3 OPENING SCREEN
COMTECH CDM-500 MODEM
S/N 0102 S/W VER 1.01
This screen is displayed whenever power is first applied to the unit. Pressing any key will
take the user to the top level selection screen:
6.4 SELECT
SELECT: CONFIG TEST INFO
MONIT STORE/LD UTIL ODU
The user is presented with the following choices:
CONFIG (Configuration) This menu branch permits the user to fully configure the unit.
TEST This menu branch permits the user invoke one of several test modes (loopbacks, for
example).
INFO (Information) This menu branch permits the user to view information on the unit, without having to
go into configuration screens.
MONIT (Monitor) This menu branch permits the user to monitor the alarm status of the unit, to view the
log of stored events, and to display the Receive Parameters screen.
STORE/LD (Store/Load) This menu branch permits the user to store and to retrieve up to 10 different modem
configurations.
UTIL (Utility) This menu branch permits the user to perform miscellaneous functions, such as
setting the Real-time clock, adjusting the display brightness, etc.
ODU (Outdoor Unit) This permits the user to monitor and control a Comtech RF Transceiver, if connected.
Each of these options is now described in detail.
6–4 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.5 CONFIG:
CONFIG: ALL TX RX FRAME
INTFC REMCONT MASK IMPED
The sub-branches available are:
ALL This menu sub-branch permits the user to completely configure the unit, being
prompted, step by step, to make choices, or edit data. This is highly recommended
for new users, as it will clearly demonstrate all the parameters which need to be set.
TX (Transmit) This menu sub-branch permits the user to define, on a parameter-by-parameter
basis, the transmit configuration of the unit. These menu sub-branches would be
used if the user wished to change, for example, just the Transmit frequency.
RX (Receive) This menu sub-branch permits the user to d efine, on a parameter-by-parameter
basis, the receive configurat ion of the unit. These menu sub-branches would be
used if the user wished to change, for example, just the receive d ata rate.
FRAME This menu sub-branch permits the user to define if the unit should operate in a
transparent mode (no framing) or i n a framed mode. In the framed mode, an
overhead of 5% is added to the rate transmitted over the satellite so that M&C
information may be passed to the distant end.
INTFC (Interface) This menu sub-branch permits the user to define which elect ri cal interface type is
active at the data connector.
REMCONT
(Remote Control)
MASK This menu sub-branch permits the user to mask certain traffic alarms, which may
IMPED
(Impedance)
Each of these options is now described in detail.
This menu sub-branch permits the user to define whether the unit is being
controlled locally, or remotely.
IMPORTANT NOTE:
The unit may be monitored over the remote control bus at any time. When in Local
mode, however, configuration parameters may only be changed through the front
panel. Conversely, when in Remote mode, the unit may be monitored from the
front panel, but configuration parameters via may only be changed remote control
bus.
cause problems to the user. As an example, certain multiplexers use ‘all ones’ as an
idle pattern. However, by convention, the ‘all ones’ condition is taken to be the
Alarm Indication Signal (AIS). The CDM-500 monitors for the AIS condition, and
if desired, this alarm may be masked.
This menu sub-branch permits the user to define the impedance at the IF
connectors, either 50 or 75 ohms.
6.5.1 (CONFIG) TX (Transmit)
TX: MOD FREQ DATA FEC
ON/OFF PWR SCRAM CLK TSI
The sub-branches available are:
Rev. 1.3 6–5
Front Panel Operation CDM-500 Closed Network Satellite Modem
6.5.2 (CONFIG, TX) MOD (Modulation)
SELECT TX MODULATION:
BPSK QPSK (PRESS ENTER)
Select BPSK or QPSK modulation, using the LEFT/RIGHT arrow keys, then press
ENTER.
6.5.3 (CONFIG, TX) FREQ (Frequency)
EDIT TX FREQUENCY:
72.2345 MHz (PRESS ENT)
Edit the transmit frequency by selecting the digit to be edited, using the LEFT/RIGHT
arrow keys. Change the value of the digit using the UP/DOWN arrow keys. Press
ENTER. The range of frequencies is from 52 - 88 MHz (70 MHz factory option) or 104 176 MHz (140 MHz factory option).
6.5.4 (CONFIG, TX) DATA (Data Rate)
EDIT TX DATA RATE:
512.000 kbps (PRESS ENT)
Edit the transmit data rate by selecting the digit to be edited, using the LEFT/RIGHT
arrow keys. Change the value of the digit using the UP/DOWN arrow keys. Press
ENTER. The overall range of data rates is from 2.4 to 512 kbps.
NOTE: The minimum and maximum data rates are dependent on modulation type and
FEC encoder rate. If the user changes the modulation or FEC, and the currently selected
data rate is then invalid, it will be adjusted automatically.
6.5.5 (CONFIG, TX) FEC (Forward Error Correction)
SELECT FEC ENCODER RATE:
1/2 3/4 7/8(PRESS ENT)
Select either Rate 1/2, Rate 3/4 or Rate 7/8 encoding rate, using the LEFT/RIGHT arrow
keys, then press ENTER.
NOTE: If BPSK is selected, only Rate 1/2 is permitted. A warning screen will be
displayed if this sub-branch is entered when in BPSK mode.
6.5.6 (CONFIG, TX) ON/OFF
SELECT TX OUTPUT STATE:
ON OFF (PRESS ENTER)
Select ON or OFF, using the LEFT/RIGHT arrow keys, then press ENTER.
6–6 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.5.7 (CONFIG, TX) PWR (Power)
EDIT OUTPUT POWER LEVEL:
-03.9 dBm (PRESS ENTER)
Edit the output power level, over the range 0 to -20 dBm, by selecting the digit to be
edited, using the LEFT/RIGHT arrow keys). Change the value of the digit using the
UP/DOWN arrow keys. Press ENTER.
6.5.8 (CONFIG, TX) SCRAM (Scrambling)
SELECT TX SCRAMBLING:
OFF ON (PRESS ENTER)
Select ON or OFF, using the LEFT/RIGHT arrow keys, then press ENTER. When
Transparent mode is selected, a V.35 scrambler is used. In Framed mode, a frame
synchronised scrambler is used.
6.5.9 (CONFIG, TX) CLK (Clocking)
SELECT TX CLOCKING MODE:
INT EXT LOOP-TIMED (ENT)
Select either INT (Internal), EXT (External) or LOOP-TIMED, using the LEFT/RIGHT
arrow keys, then press ENTER.
INTERNAL indicates that the CDM-500 will supply a clock to the DTE, which is
derived from its internal high-stability source.
EXTERNAL indicates that the CDM-500 expects to receive a clock from the DTE, to
which the unit can phase-lock its internal circuits.
LOOP-TIMED indicates that the transmit tim ing source should be the receiv e clock , from
the direction of the satellite. This is a useful mode, in that no external connection needs to
be made in this mode. If the demodulator loses lock, or if there is no receive signal
present, the internal clock is substituted.
6.5.10 (CONFIG, TX) TSI (Transmit Spectral Invert)
SELECT TRANSMIT SPECTRAL
INVERSION: OFF ON(ENTER)
Select OFF or ON, using the LEFT/RIGHT arrow keys, then press ENTER. When in the
ON position, and QPSK is selected, the transmit spectrum is inverted (which is the same
as reversing the direction of phase rotation in the modulator). In BPSK, the time-order of
bits out of the FEC encoder is reversed, to make the m odem compatible with certain other
Rev. 1.3 6–7
Front Panel Operation CDM-500 Closed Network Satellite Modem
manufacturer’s modems. (Early versions of the modem did not incorporate this feature see the INFO, MISC section for details)
6.5.11 (CONFIG) RX (Receive)
RX: MOD FRQ DATA FEC ACQ
DESCRAM CLK BUF RSI Eb/No
The sub-branches available are:
6.5.12 (CONFIG, RX) MOD (Modulation)
SELECT RX MODULATION:
BPSK QPSK (PRESS ENTER)
Select BPSK or QPSK modulation, using the LEFT/RIGHT arrow keys, then press
ENTER.
6.5.13 (CONFIG, RX) FRQ (Frequency)
EDIT RX FREQUENCY:
72.2345 MHz (PRESS ENT)
Edit the receive frequency by selecting the digit to be edited, using the LEFT/RIGHT
arrow keys. Change the value of the digit using the UP/DOWN arrow keys. Press Enter.
The range of frequencies is from 52 - 88 MHz (70 MHz factory option) or 104 - 176
MHz (140 MHz factory option).
6.5.14 (CONFIG, RX) DATA (Data Rate)
EDIT RX DATA RATE:
64.000 kbps (PRESS ENT)
Edit the receive data rate by selecting the digit to be edited, using the LEFT/RIGHT
arrow keys. Change the value of the digit using the UP/DOWN arrow keys. Press Enter.
The overall range of data rates is from 2.4 to 512 kbps. NOTE: The minimum and
maximum data rates are dependent on modulation type and FEC decoder rate. If the user
changes the modulation or FEC, and the currently selected data rate is then invalid, it will
be adjusted automatically.
6.5.15 (CONFIG, RX) FEC (Forward Error Correction)
SELECT FEC DECODER RATE:
1/2 3/4 7/8(PRESS ENT)
Select either Rate 1/2, Rate 3/4 or Rate 7/8 encoding rate, using the LEFT/RIGHT arrow
keys, then press Enter.
6–8 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
NOTE: If BPSK is selected, only Rate 1/2 is permitted. A warning screen will be
displayed if this sub-branch is entered when in BPSK mode.
6.5.16 (CONFIG, RX) ACQ (Acquisition sweep range)
EDIT RX ACQ SWEEP RANGE:
+/- 25 kHz (PRESS ENTER)
Edit the acquisition sweep range of the demodulator by selecting the digit to be edited,
using the LEFT/RIGHT arrow keys). Change the value of the digit using the UP/DOWN
arrow keys. Press Enter.
The range varies from +/- 1 kHz to +/- 30 kHz. The value entered here determines the
amount of frequency uncertainty the demodulator will sweep over in order to find and
lock to an incoming carrier. When operating at low bit rates, large values of sweep range
(compared to the data rate) will cause excessively long acquisition times. For example:
selecting +/- 30 kHz with a data rate of 2.4 kbps, BPSK, will result in an average
acquisition time of around 5 minutes.
6.5.17 (CONFIG, RX) DESCRAM (Descrambler)
SELECT RX DE-SCRAMBLING:
ON OFF (PRESS ENTER)
Select ON or OFF, using the LEFT/RIGHT arrow keys, then press Enter. When
Transparent mode is selected, a V.35 descrambler is used. In Framed mode, a framesynchronised descrambler is used. It is recommended that scrambling/descrambling be
used at all times.
6.5.18 (CONFIG, RX) CLK (Clocking)
SELECT RX CLOCKING MODE:
BUFFER ON OFF(PRESS ENT)
Select OFF or ON, using the LEFT/RIGHT arrow keys, then press Enter. When OFF is
selected, the Plesiochronous/Doppler buffer is disabled. The receive clock will then be
derived from the satellite signal, and will therefore be subject to clock offsets relative to
the local transmit clock, and a small amount (< 5%) clock jitter, due to the demodulation
bit-timing recovery process at low values of Eb/No.
When ON is selected, the Plesiochronous/Doppler buffer is enabled. The input to the
buffer will be the signal from the satellite, with any clock offsets and jitter. The output
rom the buffer will be derived from the local TRANSMIT clock. In this way, the receive
data will be perfectly synchronous with this local clock. The CDM-500 can be operated
with independent transmit receive and transmit data rates. Even in this configuration,
where RX data rate <> TX data rate, the output clock for the buffer will be phase locked
to the transmit clock. When the buffer is enabled, the size of the buffer may be selected
using the menu below:
Rev. 1.3 6–9
Front Panel Operation CDM-500 Closed Network Satellite Modem
6.5.19 (CONFIG, RX) BUF (Buffer size)
EDIT RX BUFFER SIZE:
+/-4096 BITS (PRESS ENT)
Edit the size of the Plesiochronous/Doppler Buffer in bits using the UP/DOWN arrow
keys. Press Enter. Values of +/- 256, 512, 1024, 2048 and 4096 bits are possible. If the
buffer is disabled, a warning message will be displayed if this screen is entered.
6.5.20 (CONFIG, RX) RSI (Receive spectral inversion)
SELECT RECEIVE SPECTRAL
INVERSION: OFF ON(ENTER)
Select OFF or ON, using the LEFT/RIGHT arrow keys, then press Enter. This should
normally be in the OFF position. When in the ON position, the receive spectrum is
inverted (which is the same as reversing the direction of phase rotation in the
demodulator). Note that in BPSK mode, the demodulator will automatically synchronize
to either the normal time-ordering of bits FEC codeword pairs, or the inverted ordering
used by certain other manufacturers.
6.5.21 (CONFIG, RX) Eb/No (Eb/No Alarm)
EDIT Eb/No ALARM POINT:
2.0 dB (PRESS ENTER)
Edit the Eb/No alarm point by selecting the digit to be edited, using the LEFT/RIGHT
arrow keys. Change the value of the digit using the UP/DOWN arrow keys. Press Enter.
The range of values is from 2.0 to 16.0 dB. The user may select a value here, and if the
Eb/No falls below this value, a receive traffic fault will be generated.
6.5.22 (CONFIG) FRAME (Framing Mode)
SELECT FRAMING MODE:
TRANSPARENT FRAMED (ENT)
The sub-branches available are:
6.5.23 (CONFIG, FRAME) TRANSPARENT
No framing is selected. No overhead is added, and the unit will be compatible with other
manufacturer’s equipment, when operating in a ‘standard’ configuration (IESS 308
filtering, V.35 scrambling, Viterbi).
6–10 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.5.24 (CONFIG, FRAME) FRAMED
SELECT FRAMING OPTION:
EDMAC-OFF EDMAC-ON (ENT)
Select EDMAC-OFF or EDMAC-ON, using the LEFT/RIGHT arrow keys, then press
Enter.
Embedded Distant-end Monitor And Control is enabled or disabled in this sub-menu.
If EDMAC-OFF is selected then none of the EDMAC features are available, even though
framing will still be enabled.
If EDMAC-ON is selected, the user is further prompted to select whether the unit is an
EDMAC master, or an EDMAC slave:
6.5.25 (CONFIG, FRAME, FRAMED) EDMAC-ON
SELECT EDMAC MODE:
MASTER SLAVE (ENTER)
Select MASTER or SLAVE, using the LEFT/RIGHT arrow keys, then press Enter.
An EDMAC MASTER is a unit which is local to the M&C computer, and which passes
messages, via the overhead, to a distant-end modem.
An EDMAC SLAVE is a unit which is
distant-end of a satellite link.
If MASTER is selected then the following sub-menu is displayed:
local to the M&C computer, which is at the
not
6.5.26 (CONFIG, FRAME, FRAMED, ON) EDMAC MASTER
EDIT DISTANT-END'S ADDR:
0240 (SEE HANDBOOK)(ENT)
Edit the address of the distant-end modem to which this unit will pass messages. Select
the digit to be edited with the LEFT/RIGHT arrow keys. Change the value of the digit
using the UP/DOWN arrow keys. Press Enter.
There is a restriction on values which can be entered here - they may only be in
increments of 10. This is automatically taken care of - the user may not edit the last digit
of the address. This has been implemented so that a single MASTER may pass messages
for up to 10 devices at the distant end. The valid range of addresses is from 10 to 9990.
But if SLAVE is selected, then the following sub-menu is displayed:
Rev. 1.3 6–11
Front Panel Operation CDM-500 Closed Network Satellite Modem
6.5.27 (CONFIG, FRAME, FRAMED, ON) EDMAC SLAVE
EDIT THIS UNIT'S ADDRESS
0245 (SEE HANDBOOK)(ENT)
Edit the address of this SLAVE unit. Select the digit to be edited, using the L EFT/R IGHT
arrow keys. Change the value of the digit using the UP/DOWN arrow keys. Press Enter.
The valid range of addresses is from 1 to 9999, although ‘base 10' values will be
automatically skipped.
Remember that this is a unit which is intended to be located at the distant-end of a link,
and will therefore be under the control of a MASTER at the other end. This is the
equivalent of putting the unit into Remote Control mode - no local control is possible.
6.5.28 (CONFIG) INTFC (Interface)
Select RS422 (EIA 530), V.35, or RS232 (synchronous), using the LEFT/RIGHT arrow
keys, then press ENTER.
6.5.29 (CONFIG) REMCONT (Remote control)
DATA INTERFACE: RS422
V.35 SYNC-RS232 (ENTER)
Select LOCAL or REMOTE using the LEFT/RIGHT arrow keys, then press Enter.
6.5.30 (CONFIG, LOCAL)
If LOCAL is selected then remote control will be disabled. Remote monitoring is still
possible.
6.5.31 (CONFIG, REMOTE)
SELECT REMOTE CONTROL:
LOCAL REMOTE (PRESS ENT)
If REMOTE is selected then the following sub-menus will be displayed:
If the unit has not been defined as an EDMAC SLAVE then:
REMOTE CONTROL: BAUDRATE
INTERFACE (PRESS ENTER)
Select BAUDRATE or INTERFACE, using the LEFT/RIGHT arrow keys, then press
Enter.
6–12 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.5.32 (CONFIG, REMOTE, BAUD)
If BAUD RATE is selected:
EDIT LOCAL BUS BAUDRATE:
19200 BAUD (PRESS ENTER)
Edit the baud rate of the remote control bus connected locally to the M&C computer.
Change the value using the UP/DOWN arrow keys. Press Enter. Values of 300, 1200,
2400, 4800, 9600 and 19200 baud are possible.
Note that the asynchronous character format is FIXED at 8 data bits, 1 stop bit, no parity
(8-1-N).
6.5.33 (CONFIG, REMOTE, INTFC)
If INTERFACE is selected:
ELECT. INTERFACE: RS232
RS485-2W RS485-4W (ENT)
Select RS232, RS485 (2- wire), or RS485 (4-wire), using the LEFT/RIGHT arrow keys,
then press Enter. At this point the user will be further prompted to enter the bus address.
In RS232 mode the bus address is fixed at 0, and the following screen will be displayed:
6.5.34 (CONFIG, REM, INTFC, ADDR) RS232 BUS ADDRESS
IN RS232 MODE THE BUS
ADDRESS IS FIXED AT 0000
However, if either RS485 mode is selected, the user will be further prompted:
6.5.35 (CONFIG, REM, INTFC, ADDR) RS485 BUS ADDRESS:
EDIT UNIT'S BUS ADDRESS:
0245 (PRESS ENTER)
Edit the RS485 bus address of this unit. Select the digit to be edited, using the
LEFT/RIGHT arrow keys. Change the value of the digit using the UP/DOWN arrow
keys. Press Enter. The valid range of addresses is from 1 to 9999.
6.5.36 (CONFIG) MASK (Alarm mask)
ALARM MASK: AGC Eb/No
RX-AIS BUF-SLIP TX-AIS
Select AGC, Eb/No, RX-AIS, BUF-SLIP, or TX-AIS, using the LEFT/RIGHT arrow
keys, then press Enter.
Rev. 1.3 6–13
Front Panel Operation CDM-500 Closed Network Satellite Modem
According to the choice selected, one of the following sub-menus will be displayed:
6.5.37 (CONFIG, MASK) AGC
SELECT AGC ALARM MASK:
ACTIVE MASKED(PRESS ENT)
Select ACTIVE or MASKED, using the LEFT/RIGHT arrow keys, then press Enter.
If the user selects ACTIVE, then a Receive Traffic fault will be generated whenever the
demodulator senses that the composite input level being applied will cause compression
in the IF stages, and hence degrade the performance of the demodulator.
If the user selects MASKED, no alarm will be generated under these conditions.
6.5.38 (CONFIG, MASK) Eb/No
SELECT Eb/No ALARM MASK:
ACTIVE MASKED(PRESS ENT)
Select ACTIVE or MASKED, using the LEFT/RIGHT arrow keys, then press Enter.
If the user selects ACTIVE, then a Receive Traffic fault will be generated whenever the
demodulator determines that the Eb/No of the received carrier has fallen below the
threshold defined under CONFIG, RX, Eb/No.
If the user selects MASKED, no alarm will be generated under these conditions.
6.5.39 (CONFIG, MASK) RX-AIS
SEL RX-AIS ALARM MASK:
ACTIVE MASKED(PRESS ENT)
Select ACTIVE or MASKED, using the LEFT/RIGHT arrow keys, then press Enter.
If the user selects ACTIVE, then a Receive Traffic fault will be generated whenever the
demodulator senses that the ‘all ones’ condition is present in the receive data.
If the user selects MASKED, no alarm will be generated under these conditions.
6.5.40 (CONFIG, MASK) BUF-SLIP (Buffer slip)
SEL BUF-SLIP ALARM MASK:
ACTIVE MASKED(PRESS ENT)
Select ACTIVE or MASKED, using the LEFT/RIGHT arrow keys, then press Enter.
6–14 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
If the user selects ACTIVE, then a Receive Traffic fault will be generated whenever the
receive circuitry senses that the buffer has either underflowed, or overflowed.
If the user selects MASKED, no alarm will be generated under these conditions.
6.5.41 (CONFIG, MASK) TX-AIS
SEL TX-AIS ALARM MASK:
ACTIVE MASKED(PRESS ENT)
Select ACTIVE or MASKED, using the LEFT/RIGHT arrow keys, then press Enter.
If the user selects ACTIVE, then a Transmit Traffic fault will be generated whenever the
transmit circuitry senses that the ‘all ones’ condition is present in the transmit data.
If the user selects MASKED, no alarm will be generated under these conditions.
6.5.42 (CONFIG) IMPED (IF impedance)
SELECT IF IMPEDANCE:
50 OHMS 75 OHMS (ENTER)
Select 50 ohms or 75 ohms, using the LEFT/RIGHT arrow keys, then press Enter.
Rev. 1.3 6–15
Front Panel Operation CDM-500 Closed Network Satellite Modem
6.6 TEST
TEST: NORM TX-CW TX-1,0
IF] DIG] I/O] (ENT)
Select NORM, TX-CW, TX-1,0, IF LOOP, DIG LOOP, or I/O LOOP, using the
LEFT/RIGHT arrow keys, then press Enter.
This sub-menu permits the user to select the following test modes:
NORM (Normal)This clears any test modes or loopbacks, and places the unit
back into an operational state
TX-CW (Transmit CW)This is a test mode which forces the modulator to transmit
a pure carrier (unmodulated).
TX-1,0 (Transmit an alternating 1,0,1,0 pattern)This is a test mode which forces
the modulator to transmit a carrier modulated with an alternating 1,0,1,0
pattern, at the currently selected symbol rate. This causes two discrete
spectral lines to appear, spaced at +/- half the symbol rate, about the
carrier frequency. This mode is used to check the carrier suppression of
the Modulator.
IF LOOP (IF Loopback)This test mode invokes an internal IF loop. This is a
particularly useful feature, as it permits the user to perform a quick
diagnostic test without having to disturb external cabling. Furthermore, all
of the receive configuration parameters are temporarily changed to match
those of the transmit side. When NORMAL is again selected, all of the
previous values are restored.
DIG LOOP (Digital Loopback) This test mode invokes a digital loopback, which loops
data at the output of the digital FIR filter on the transmit side, back into
the Viterbi decoder on the receive side. This tests all of the interface,
transmit baseband circuits, FEC encoder, FEC decoder, and buffer.
I/O LOOP (Inward/Outward loopback) This test mode invokes two distinct
loopbacks. The first of these is the inward loop, which takes data being
received from the satellite direction, and passes it directly to the
modulator. Simultaneously, the outward loop is invoked, whereby data
being fed to the transmit data interface is routed directly back out of the
receive data interface.
6–16 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.7 INFO (Information)
INFO:ID TX RX BUFF EDMAC
REMCONT MASK MISC(ENTER)
Select ID, TX, RX, BUFF, EDMAC, REMCONT, MASK, or MISC using the
LEFT/RIGHT arrow keys, then press Enter.
These screens display information on the current configuration of the unit.
Depending on the choice selected, one of the following screens will be displayed:
6.7.1 (INFO) ID (Circuit ID)
CIRCUIT ID: (ENTER)
THIS IS A TEST MESSAGE
This displays the user-defined Circuit ID string, which is entered via the UTIL, ID
screen. To return to the previous menu, then press Enter.
6.7.2 (INFO) TX (Transmit information)
Tx:140.0000M 512.000k F
Q R1/2 S LOP -20.0 ON I
The information displayed here is as follows:
Top line, left to right:
Transmit Frequency
•
Transmit Data Rate
•
Framing status (F = framing on, T = transparent)
•
Bottom line, left to right:
Modulation type (Q = QPSK, B = BPSK)
•
Code Rate
•
Scrambler state (S = Scrambler on, N = Scrambler off)
•
Clocking Mode (INT = internal, EXT = external, LOP = loop)
•
Output power level
•
Transmit output state (ON = on , OFF = off, EOF = external off)
•
TSI state (I = Transmit Spectral Inversion on, N = off)
•
6.7.3 (INFO) RX (Receive information)
Rx:140.0000M 512.000k F
B R3/4 D BUFF +/-23.5k I
Rev. 1.3 6–17
Front Panel Operation CDM-500 Closed Network Satellite Modem
The information displayed here is as follows:
Top line, left to right:
Receive Frequency
•
• Receive Data Rate
Framing status (F = framing on, T = transparent)
•
Bottom line, left to right:
Modulation type (Q = QPSK, B = BPSK)
•
• Code Rate
Descrambler state (D = Descrambler on, N = off)
•
Clocking Mode
•
Demod Sweep Acquisition range
•
RSI state (I = Receive Spectral Inversion on, N = off)
•
6.7.4 (INFO) BUFF (Buffer information)
BUFFER: ENABLED (TX=RX)
SIZE: +/-4096 BITS
This displays if the buffer is enabled or disabled, shows the exact clocking mode
(TX=RX, or TX<> RX), and the buffer size. Press Enter to return to the previous menu.
6.7.5 (INFO) EDMAC (Framing and EDMAC information)
FRAMING: ON
EDMAC MODE: ON (SLAVE)
This screen shows the framing mode, EDMAC mode, and shows if the unit is an
EDMAC MASTER or SLAVE. Press Enter to return to the previous menu.
6.7.6 (INFO) REMCONT (Remote Control information)
REM-CONTROL:ON RS485-4W
ADDRESS: 0001 19200 BAUD
This screen shows if the unit is in LOCAL or REMOTE mode, and gives details of the
electrical interface type selected, the unit’s address, and the baud rate selected. Press
Enter to return to the previous menu.
6.7.7 (INFO) MASK (Alarm mask information)
ALARMS MASKED:
RX-AIS TX-AIS
This shows, in the same format as the CONFIG, MASK sub menu, which alarms are
currently masked. If an alarm is not masked, a blank is displayed in the relevant screen
position.
6–18 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.7.8 (INFO) MISC (Miscellaneous information)
MISC: IF-LOOP 50 OHMS *
1:1 LINK IDLE ONLINE
This screen shows the following:
• Test mode
IF impedance
•
• 1:1 link status - if the CRS-100 1:1 module is being used, this shows the
status of the serial link between the two units.
Redundancy status - either online or standby (1:1 or 1:N)
•
IMPORTANT NOTE: If the asterix shown in the top right is present, this means that the
hardware and software support the ‘codeword time-swap’ feature when TSI is selected in
BPSK mode. If the asterix is not shown, the modem does not support this feature. In
general, these are modems prior to S/N 150, and Software prior to V.1.07.
Press Enter to return to the previous menu.
Rev. 1.3 6–19
Front Panel Operation CDM-500 Closed Network Satellite Modem
6.8 MONIT (Monitor)
SELECT MONITOR: ALARMS
STORED EVENTS RX-PARAMS
Select ALARMS, STORED EVENTS, or RX-PARAMS using the LEFT/RIGHT arrow
keys, then press Enter.
If the user selects ALARMS, the following sub-menu is displayed:
6.8.1 (MONIT) ALARMS
LIVE ALARMS: UNIT
RECEIVE TRANSMIT
Select UNIT, RECEIVE or TRANSMIT, using the LEFT/RIGHT arrow keys, then press
Enter.
Depending on the choice selected, one of the following menus will be displayed:
6.8.2 (MON, ALARMS) UNIT (Unit alarms)
UNIT FAULT: -12 VOLT PSU
IS UNDER-VOLTAGE
The screen will indicate if there are any Unit Faults. If not, it will display ‘NONE’. Press
Enter to return to the previous menu.
6.8.3 (MON, ALARMS) RECEIVE (Receive alarms)
RX TRAFFIC: AGC ALARM
REDUCE COMPOSITE I/P LVL
The screen will indicate if there are any Receive Traffic Faults. If not, it will display
‘NONE’. Press Enter to return to the previous menu.
6.8.4 (MON, ALARMS) TRANSMIT (Transmit alarms)
TX TRAFFIC: NO CLOCK
DETECTED FROM INTERFACE
The screen will indicate if there are any Transmit Traffic Faults. If not, it will display
‘NONE’. Press Enter to return to the previous menu.
If the user selects STORED EVENTS, the following sub-menu is displayed:
6–20 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.8.5 (MONIT) STORED EVENTS
STORED EVENTS: VIEW
CLEAR ALL (PRESS ENTER)
Select VIEW or CLEAR ALL, using the LEFT/RIGHT arrow keys, then press Enter.
If the user selects VIEW, the following screen is displayed:
6.8.6 (MON, EVENTS) VIEW
LOG23: 30/11/97 10:37:32
FT - DEMOD LOCK (UP/DWN)
Scroll backwards or forwards through the entries in the event log, using the UP/DOWN
arrow keys. Press ENTER or CLEAR to return to the previous menu. The event log can
store up to 100 events. When a fault condition occurs, it is time-stamped and put into the
log. Similarly, when the fault condition clears, this is also recorded, as shown below:
LOG24: 30/11/97 10:37:35
OK - DEMOD LOCK (UP/DWN)
If the user selects CLEAR ALL, the event log is cleared, and the user is taken directly
back to the previous menu. However, if there are faults present on the unit at this time,
they will be re-time-stamped, and new log entries will be generated.
If the user selects RX-PARAMS, the following sub-menu is displayed:
Rev. 1.3 6–21
Front Panel Operation CDM-500 Closed Network Satellite Modem
6.8.7 (MONIT) RX-PARAMS (Receive Parameters)
RX:EbNo=5.7dB dF=+11.7k
BER=3.4E-9 BUF-FILL=50%
If the demodulator is locked, this screen shows the following:
Eb/No This shows the value of Eb/No calculated by the demodulator.
The value referred to here is the energy per information bit
(Ebi), divided by the noise spectral density (No).
dF This is the frequency offset of the received carrier, in kHz, with
a displayed resolution of 100 Hz.
BER This is an estimate of the corrected BER. This figure is derived
from an accurate measurement of the uncorrected error rate
(from the Viterbi decoder), applied to a look-up table.
BUF-FILL (Buffer fill state) This gives the value, in percent, of the current
fill state of the Plesiochronous-Doppler Buffer. Following a
reset, it will read 50%. A value < 50% indicates that the buffer
is emptying, and >50% indicates that it is filling.
If the demodulator is not locked, this screen shows the message ‘DEMODULATOR
NOT LOCKED’. Pressing ENTER or CLEAR will take the user back to the previous
menu.
6–22 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.9 STORE/LD (Store/Load)
STORE/LOAD CONFIG:
STORE LOAD (PRESS ENTER)
Select STORE or LOAD using the LEFT/RIGHT arrow keys, then press Enter.
These sub-menus permit the user to store or load up to 10 different modem configurations
in the non-volatile memory of the modem
Selecting STORE will display the following screen:
6.9.1 (STORE/LD) STORE
STORE CONFIGURATION TO
LOCATION: 10 (ENTER)
Select the location to store the current configuration to, using the UP/DOWN arrow keys,
then press Enter. Locations 1 through 10 are available.
If the selected location does not contain a previously stored configuration, the following
screen is displayed:
YOUR CONFIGURATION HAS
BEEN STORED! (ENTER)
Press ENTER or CLEAR to return to the previous menu.
If, however, the selected location contains a previously stored configuration, the
following screen is displayed:
WARNING! LOC 10 CONTAINS
DATA! OVERWRITE? NO YES
Select NO or YES using the LEFT/RIGHT arrow keys, then press Enter.
Selecting YES will overwrite the existing configuration at the selected location.
Selecting STORE will display the following screen:
6.9.2 (STO/LD) LOAD
LOAD CONFIGURATION FROM
LOCATION: 10 (ENTER)
Rev. 1.3 6–23
Front Panel Operation CDM-500 Closed Network Satellite Modem
Select the location to load a configuration from, using the UP/DOWN arrow keys, then
press Enter. Locations 1 through 10 are available.
If the selected location contains valid data, the following screen will
be displayed:
THE NEW CONFIGURATION
HAS BEEN LOADED (ENTER)
Press ENTER or CLEAR to return to the previous menu.
If, however, the selected location does not contain valid data, the following screen will be
displayed:
WARNING! LOC 10 CONTAINS
NO DATA! (ENTER)
Press ENTER or CLEAR to return to the previous menu.
6–24 Rev. 1.3
CDM-500 Closed Network Satellite Modem Front Panel Operation
6.10 UTIL (Utility)
UTILITY: SET-RTC DISPLAY
MAN-1:1 RECENTER-BUF ID
Select SET-RTC, DISPLAY MAN-1:1, RECENTER-BUF, OR ID, using the
LEFT/RIGHT arrow keys, then press Enter.
This sub-menu permits the user to select from a number of different utility functions,
which are described below:
6.10.1 (UTIL) SET-RTC (Set real-time clock)
EDIT REAL TIME CLOCK:
12:00:00 24/04/98 (ENT)
Edit the time and date settings of the real-time clock by selecting the digit to be edited,
using the LEFT/RIGHT arrow keys. Change the value of the digit using the UP/DOWN
arrow keys. Note that in accordance with international convention, the date is shown in
DAY-MONTH-YEAR format. Press Enter.
6.10.2 (UTIL) DISPLAY (Display brightness)
EDIT DISPLAY BRIGHTNESS:
100% (PRESS ENTER)
Edit the display brightness, using the UP/DOWN arrow keys. Press Enter.
6.10.3 (UTIL) MAN-1:1 (Manual 1:1 switchover)
PRESS ENT TO FORCE THIS
UNIT TO STDBY (1:1 ONLY)
If the unit is part of a 1:1 redundant pair of modems, and this unit is currently on-line,
pressing ENTER will cause the unit to switch to standby.
6.10.4 (UTIL) RECENTER-BUF (re-center buffer)
PRESS ENTER TO RE-CENTER
THE RECEIVE BUFFER
Press ENTER to cause a forced re-centering of the Plesiochronous/Doppler buffer.
Rev. 1.3 6–25
Front Panel Operation CDM-500 Closed Network Satellite Modem
6.10.5 (UTIL) ID (Circuit ID)
EDIT CIRCUIT ID: (ENTER)
THIS IS A TEST MESSAGE
Edit the Circuit ID string, using the LEFT/RIGHT and UP/DOWN arrow keys. Only the
bottom line is available (24 characters). The cursor selects the position on the bottom line
(LEFT/RIGHT) and the character is then edited (UP/DOWN). The following characters
are available:
Space ( ) * + - , . / 0-9 and A-Z.
After composing the string, press Enter.
6–26 Rev. 1.3
When dealing with satellite modems, the subject of clocking can be a com plex issue. This
section describes the various clocking options which are available with the CDM-500.
7.1 Transmit Clocking
There are three transmit clocking modes in the CDM-500. EIA-422/449 signal
mnemonics will be used for illustration, but the description applies equally to V.35, and
synchronous EIA-232.
7.1.1 Internal Clock
Chapter 7.
CLOCKING
7
In this mode, the modem, assumed always to be the DCE, supplies the clock to the DTE.
(The EIA-422/449 name for this signal is Send Timing, or ST.) The DTE then clocks
from this source, and gives the modem transmit data (Send Data, or SD), synchronous
with this clock. It is optional whether the DTE also returns the clock (Terminal Timing,
or TT) – the modem can accept if it is present, but uses ST if is not.
7.1.2 External Clock
In this mode, the modem expects to see the DTE provide the clock, so that it can phaselock its internal circuits. In this case, the modem does not provide any signal on ST, but
instead requires a clock signal on Terminal Timing (TT), synchronous with the data. If no
clock is present, an alarm will be generated.
Rev. 1.3 7–1
Clocking CDM-500 Closed Network Satellite Modem
7.1.3 Loop-Timed
In certain circumstances, a terminal at the distant-end of a satellite link may be required
to provide a clock to the DTE equipment which is locked to the receive satellite signal.
This is similar to Internal Clock mode, in that the modem will source Send Timing (ST)
to the DTE, but now the timing is derived from the demodulator. The DTE then clocks
from this source, and gives the modem transmit data (Send Data, or SD), synchronous
with this clock. It is optional whether the DTE also returns the clock (Terminal
Timing, or TT) - the modem can accept if it is present, but uses ST if it is
not. If the demodulator loses lock, the modem’s internal clock will be
substituted, so an accurate and stable clock is present on ST, rather than
a clock which may jitter and wander in a random fashion.
7.2 Receive Clocking
Like the transmit side, there are three receive clocking modes in the CDM-500.
7.2.1 Buffer Disabled
When the buffer is disabled, the receive clock (Receive Timing , or R T) is deriv ed directly
from the demodulator, and hence will be subject to plesiochronous and Doppler offsets.
In certain instances, this may be acceptable, and in the case of Loop Timing, it is
essential that the buffer is disabled (which is done automatically).
7.2.2 Buffer Enabled, Rx=Tx
In this instance, it is required that buffer be enabled, so that the clock and data appearing
on Receive Timing and Receive Data (RT and RD respectively) are synchronous with the
transmit clock. This is a relatively simple case, as the output clock for the buffer is
derived directly from either ST or TT.
7.2.3 Buffer Enabled, Rx<>Tx
This is an uncommon case, where the receive and transmit data rates are not equal. The
modem will generate a phase-locked buffer output clock which uses the transmit clock,
regardless of its frequency in relation to the receive data rate.
7.3 X.21 Notes
For X.21 operation, use the EIA-422 pins, but ignore Receive Clock if the Modem is
DTE, and ignore Transmit clocks if the Modem is DCE.
7–2 Rev. 1.3
8.1 Theory Of Operation
As explained earlier, EDMAC is an acronym for Embedded Distant-end Monitor And
Control. This is a feature which permits the user to access the M&C features of modems
which are at the distant-end of a satellite link. This is accomplished by adding extra
information to the user’s data, but in a manner which is completely transparent to the
user.
On the transmit side:
The data is split into frames - each frame containing 1008 bits. 960 of these bits are the
user’s data, the remaining 48 bits are overhead. This increases the rate of transmission by
5%. (For example, if the user’s data rate is 64 kbps, the actual transmission rate will now
be at 67.2 kbps)
At the start of each frame a 12 bit synchronization word is added. This allows the
demodulator to find and lock to the start of frame. At regular intervals throughout the
frame additional data bytes and flag bits are added (a further 36 bits in total). It is these
additional bytes which convey the M&C data.
When framing is used, the normal V.35 scrambler is no longer used. This V.35 approach
is called ‘self synchronizing’, because in the receiver, no external information is required
in order for the de-scrambling process to recover the original data. The disadvantage of
this method is that it multiplies errors. On average, if one bit error is present at the input
of the descrambler, 3 output errors are generated. However, there is an alternative when
the data is in a framed format. In this case, a different class of scrambler may be used one which uses the start of frame information to start the scrambling process at an exact
known state. In the receiver, having synchronised to the frame, the de-scrambler can
begin its processing at exactly the right time. This method does not multiply errors, and
Chapter 8.
EDMAC CHANNEL
8
Rev. 1.3 8–1
EDMAC Channel CDM-500 Closed Network Satellite Modem
therefore has a clear advantage over V.35 scrambling. This is fortunate, as there is a
penalty to be paid for adding the framing. By adding the extra 5% to the transmitted data
rate, the effective Eb/No seen by the user will degrade by a factor of 10log(1.05), or 0.21
dB. The use of an externally synchronized scrambler and descrambler almost exactly
compensates for this degradation. The net effect is that the user will see effectively
identical BER performance whether framing is used or not.
On the receive side:
When the demodulator locks to the incoming carrier, it must go through the additional
step of searching for, and locking to the synchronization word. This uniquely identifies
the start of frame, and permits the extraction of the overhead bytes and flag bits at the
correct position within the frame. In addition, the start of frame permits the de-scrambler
to correctly recover the data. The user’s data is extracted, and sent through additional
processing, in the normal manner. The extracted overhead bytes are examined to
determine if they contain valid M&C bytes.
8.2 M&C Connection
Data to be transmitted to the distant-end is sent to a local unit via the remote control port.
A message for the distant-end is indistinguishable from a ‘local’ message - it has the
same structure and content, only the address will identify it as being for a distant-end
unit.
Before the M&C data can be successfully transmitted and received, pairs of units must be
split into EDMAC Masters and EDMAC Slaves. Masters are local to the M&C
Computer, and Slaves are distant-end.
Now, a unit which has been designated an EDMAC master not only responds to its own
unique bus address, but it will also be configured to listen for the address which
corresponds to its EDMAC Slave. When a complete message packet has be received by
the EDMAC Master, it will begin to transmit this packet over the satellite channel, using
the overhead bytes which become available.
(Note: The ‘normal’ protocol for the message packet is not used over the satellite path, as
it is subject to errors. For this reason, a much more robust protocol is used which
incorporates extensive error checking.)
At the distant-end, the EDMAC slave, configured for the correct address, receives these
bytes, and when a complete packet has been received, it will take the action requested,
and then send the appropriate response to the EDMAC Master, using the return overhead
path on the satellite link. The EDMAC Master assembles the complete packet, and
transmits the response back to the M&C Computer.
Apart from the round-trip satellite delay, the M&C Computer does not see any difference
between local and distant-end units - it sends out a packet, addressed to a particular unit,
and gets back a response. In can be seen that the EDMAC Master simply acts as
forwarding service, in a manner which is completely transparent.
8–2 Rev. 1.3
CDM-500 Closed Network Satellite Modem EDMAC Channel
This approach does not require any additional cabling - connection is made using the
normal M&C remote port. Furthermore, the user does not have to worry about
configuring the baud rate of the M&C connection to match the lowest data rate modem in
the system. The M&C system can have mixed data-rate modems, from 2.4 kbps to 512
kbps, and still run at 19,200 baud. (It should be pointed out that at 2.4 kbps, the effective
throughput of the overhead channel is only 11 async characters/second. For a message of
24 bytes, the time between sending a poll request and receiving a response will be around
5 seconds.)
8.3 Setup Summary
To access a distant-end unit:
Designate a Master/Slave pair - Master at the local-end, Slave at the distant-end
•
On the local-end unit, enable framing, and EDMAC, define the unit as MASTER,
•
then enter the bus address of the SLAVE. This is constrained to be ‘base 10'
meaning that only addresses such as 10, 20, 30, 40 etc, are allowed.
Choose a unique bus address for the distant-end. This should normally be set to
•
the ‘base 10' address + 1. For example, if the MASTER unit is set to 30, choose
31 for the distant-end unit.
On the distant-end unit, enable framing, and EDMAC, define the unit as SLAVE,
•
then enter the bus address. The orange EDMAC Mode LED should be
illuminated.
Set the local-end unit to RS485 remote control, and set the bus address of this
•
local unit. The orange Remote Mode LED should be illuminated.
Once the satellite link has been established, connect the M&C Computer, and
•
begin communications, with both the local and distant end units.
Rev. 1.3 8–3
EDMAC Channel CDM-500 Closed Network Satellite Modem
This page has been intentionally left blank.
8–4 Rev. 1.3
SUMMARY OF SPECIFICATIONS
A.1 Modulator
Data rate range Overall, 2.4 - 512 kbps
2.4 kbps - 256 kbps, Rate 1/2 BPSK
4.8 kbps - 512 kbps Rate 1/2 QPSK
7.2 kbps - 512 kbps Rate 3/4 QPSK
8 kbps - 512 kbps Rate 7/8 QPSK
Operating modes Transparent, Closed Network
Proprietary EDMAC framed mode - 5% overhead
addition
Scrambling Transparent mode - per CCITT V.35
EDMAC mode - externally synchronized
FEC Convolutional, k=7, standard polynomials
BPSK: Rate 1/2
QPSK: Rate 1/2, Rate 3/4 and Rate 7/8
Transmit filtering 6th order Butterworth, aperture and group delay
equalised per INTELSAT IESS 308 (32 to 256 tap FIR
digital filter implementation)
Output frequency 52 - 88 MHz, 100 Hz resolution
(140 MHz band optional, 104 - 176 MHz)
Stability ±1ppm, 0 to 40° C
Harmonics and
spurious
Transmit on/off
ratio
Output phase
noise
Output power 0 to -20 dBm, 0.1 dB steps
Accuracy ±0.5 dB over frequency and temperature
Better than -55 dBC/4 kHz (typically <-60 dBC/4kHz)
55 dB minimum
< 0.24 rms double sided, 100 Hz to 250 kHz
(minimum of 22 dB better overall than the INTELSAT
IESS 308/308 requirement)
Appendix A.
A
Rev. 1.3 A–1
Spec Summary CDM-500 Closed Network Satellite Modem
Output
impedance
Output
50 and 75 ohms, front panel selectable
17 dB minimum return loss
BNC female
connector
Clocking options Internal, ±1ppm
External, locking over a ±100 ppm range
Loop timing (Rx satellite clock)
External TX
Carrier Off
By TTL 'low' signal o r external contact clo sure
hardware function automatically over-rides processor
A.2 Demodulator
(Data rate range, operating modes, de-scrambling, input impedance/return loss etc, as per Modulator specs)
Input power
range
FEC Viterbi, 3 bit soft decision
Acquisition
range
Acquisition
time
Clock tracking
range
BER
Performance
(met in the
presence of
two adjacent
carriers, each
7 dB higher
than the
desired carrier)
Buffer Plesiochronous/Doppler buffer with selectable size of
Monitor
Functions
-30 to -60 dBm (desired carrier)
-8 dBm max composite
±1 to ±32 kHz, programmable in 1kHz increments
Highly dependent on data rate, FEC rate, and demodulator
acquisition range. Examples:
250 milliseconds average at 512 kbps, R1/2 QPSK, ±30kHz
acquisition sweep range, 6dB Eb/No
5 seconds average at 16 kbps, R1/2 QPSK, ±5kHz acquisition
range, 6dB Eb/No
21 seconds average at 8.2 kbps, R7/8 QPSK, ±2kHz acquisition
sweep range, 6dB Eb/No
Note that Rate 3/4 and Rate 7/8 FEC rates slow acquisition time
considerably, due to the additional time taken for the Viterbi
decoder to declare synchronization.
± 100 ppm min
For:
BER=10
BER=10
BER=10
-5
-6
-7
512, 1024, 2048, 4096 or 8192 bits
Eb/No estimate
Corrected Bit Error Rate
Frequency offset
Buffer fill state
Rate 1/2
Guaranteed
Eb/No:
(typical value
in parentheses)
5.4dB (4.9 dB)
6.0dB (5.5 dB)
6.7dB (6.2 dB)
Rate 3/4
Guaranteed
Eb/No:
(typical value
in parentheses)
6.8dB (6.3 dB)
7.4dB (6.9 dB)
8.2dB (7.7 dB)
Rate 7/8
Guaranteed
Eb/No:
(typical value
in parentheses)
7.7dB (7.2 dB)
8.4dB (7.9 dB)
9.0dB (8.6 dB)
A–2 Rev. 1.3
CDM-500 Closed Network Satellite Modem Spec Summary
A.3 Data Interfaces
Built in RS422/EIA530 DCE (also supports X.21 DCE and DTE)
V.35 DCE
Synchronous RS232
(Front panel selectable)
Pinout Per EIA530 (25 pin ‘D’ type female)
A.4 Miscellaneous
Front panel Tactile keypad, 6 keys (Up/Down, Left/Right, Enter/Clear)
Vacuum Fluorescent Display (blue) - 2 lines of 24
characters
Loopbacks Internal IF, digital, and near/far
Fault relays Hardware fault, Rx and Tx Traffic Alarms
M&C Interface RS232 and RS485 (addressable multidrop)
RS485 may be either 2-wire or 4-wire
M&C Software EDMAC software for control of local and distant units
Dimensions 1U high, 12 inches (305 mm) deep
Weight 7 lbs (3.2 kgs) max
AC
consumption
Operating
voltage
Operating temp 0 to 50 C
18 watts (typical)
25 watts (maximum)
100 - 240 volts AC, +6%/-10% - autosensing
(total absolute max. range is 90 - 254 volts AC)
A.5 Approvals
CE’ as follows:
FCC
EN 55022 Class B (Emissions)
EN 50082-1 (Immunity)
EN 60950 (Safety)
FCC Part 15 Class B
Rev. 1.3 A–3
Spec Summary CDM-500 Closed Network Satellite Modem
Figure A-1 BER Viterbi Decoding
A–4 Rev. 1.3
B.1 Introduction
This section describes the protocol and message command set for remote monitor and
control of the CDM-500 Modem.
The electrical interface is either an EIA-485 multi-drop bus (for the control of many
devices) or an EIA-232 connection (for the control of a single device), and data is
transmitted in asynchronous serial form, using ASCII characters. Control and status
information is transmitted in packets, of variable length, in accordance with the structure
and protocol defined in later sections.
Appendix B.
REMOTE CONTROL
B
B.2 EIA-485
For applications where multiple devices are to be monitored and controlled, a full-duplex
(or 4-wire plus ground) EIA-485 is preferred. Half-duplex (2-wire plus ground) EIA-485
is possible, but is not preferred.
In full-duplex EIA-485 communication there are two separate, isolated, independent,
differential-mode twisted pairs, each handling serial data in different directions. It is
assumed that there is a ‘controller’ device (a PC or dumb terminal), which transmits data,
in a broadcast mode, via one of the pairs. Many ‘target’ devices are connected to this
pair, which all simultaneously receive data from the controller. The controller is the only
device with a line-driver connected to this pair - the target devices only have linereceivers connected.
Rev. 1.3 B–1
Remote Control CDM-500 Closed Network Satellite Modem
In the other direction, on the other pair, each target has a tri-stateable line driver
connected, and the controller has a line-receiver connected. All the line driv ers are held in
high-impedance mode until one (and only one) target transmits back to the controller.
Each target has a unique address, and each time the controller transmits, in a framed
‘packet’ of data, the address of the intended recipient target is included. All of the targets
receive the packet, but only one (the intended) will reply. The target enables its output
line driver, and transmits its return data packet back to the controller, in the other
direction, on the physically separate pair.
EIA 485 (full duplex) summary:
Two differential pairs - one pair for controller to target, one pair for target to
•
controller.
Controller-to-target pair has one line driver (controller), and all targets have line-
•
receivers.
Target-to-controller pair has one line receiver (controller), and all targets have
•
tri-state drivers.
B.3 EIA-232
This a much simpler configuration in which the controller device is connected directly to
the target via a two-wire-plus-ground connection. Controller-to-target data is carried, via
EIA-232 electrical levels, on one conductor, and target-to-controller data is carried in the
other direction on the other conductor.
B.4 Basic Protocol
Whether in EIA-232 or EIA-485 mode, all data is transmitted as asynchronous serial
characters, suitable for transmission and reception by a UART. In this case, the
asynchronous character format is fixed at 8 data bits, one stop bit, no parity. The baud
rate may vary between 50 baud and 19,200 baud.
All data is transmitted in framed packets. The controller is assumed to be a PC or ASCII
dumb terminal, which is in charge of the process of monitor and control. The controller is
the only device which is permitted to initiate, at will, the transmission of data. Targets are
only permitted to transmit when they have been specifically instructed to do so by the
controller.
All bytes within a packet are printable ASCII characters, less than ASCII code
127. In this context, the Carriage Return and Line Feed characters are considered
printable.
All messages from controller to target require a response (with one exception).
This will be either to return data which has been requested by the controller, or
to acknowledge reception of an instruction to change the configuration of the
B–2 Rev. 1.3
CDM-500 Closed Network Satellite Modem Remote Control
target. The exception to this is when the controller broadcasts a message (such
as Set time/date) using Address 0, when the target is set to EIA-485 mode.
B.5 Packet Structure
Controller-to-target:
Start of Packet
<
ASCII code60
(1 character) (4 characters)
Start of
Packet
<
ASCII code62
(1 character) (4 characters)
Target
Address
Address
De-limiter
/
ASCII code 47
(1 character) (3 characters)
Instruction
Code
Code
Qualifier
= or ?
ASCII code
61 or 63
(1 character) (n characters)
Example: <0135/TFQ=70.2345{CR}
Target-to-controller:
Target
Address
Address
De-limiter
/
ASCII code 47
(1 character) (3 characters)
Instruction
Code
Code
Qualifier
= or ?
ASCII code
61, 33 or 42
(1 character)
Example: >0654/RSW=32{CR}{LF}
Each of the components of the packet is now explained.
Optional
Arguments
Optional
Arguments
(From 0 to n
characters)
End of Packet
Carriage
Return
ASCII code 13
(1 character)
End of Packet
CarriageReturn
Line Feed
ASCII code
13,10
(2 characters)
B.5.1 Start Of Packet
Controller to Target: This is the character ‘<’ (ASCII code 61)
Target to Controller: This is the character ‘>’ (ASCII code 62)
Because this is used to provide a reliable indication of the start of packet, these two
characters may not appear anywhere else within the body of the message.
B.5.2 Address
Up to 9,999 devices can be uniquely addressed. In EIA-232 applications this value is set
to 0. In EIA-485 applications, the permissible range of values is 1 to 9999. It is
programmed into a target unit using the front panel keypad. Important note: The
controller sends a packet with the address of a target – the destination of the packet.
When the target responds, the address used is the same address, to indicate to the
controller the source of the packet. The controller does not have its own address.
Rev. 1.3 B–3
Remote Control CDM-500 Closed Network Satellite Modem
B.5.3 Instruction Code
This is a three-character alphabetic sequence which identifies the subject of the message.
Wherever possible, the instruction codes have been chosen to have some significance.
For example TFQ for transmit frequency, RMD for receive modulation type, etc. This
aids in the readability of the message, should it be displayed in its raw ASCII form. Only
upper case alphabetic characters may be used (A-Z, ASCII codes 65 - 90).
B.5.4 Instruction Code Qualifier
This is a single character which further qualifies the preceding instruction code.
Code Qualifiers obey the following rules:
1) From Controller to Target, the only permitted values are:
= (ASCII code 61)
? (ASCII code 63)
They have these meanings:
The ‘=’ code (controller to target) is used as the assignment operator, and is used
to indicate that the parameter defined by the preceding byte should be set to the
value of the argument(s) which follow it.
For example, in a message from controller to target, TFQ=070.0000 would mean
‘set the transmit frequency to 70 MHz’
The ‘?’ code (controller to target) is used as the query operator, and is used to
indicate that the target should return the current value of the parameter defined
by the preceding byte.
For example, in a message from controller to target, TFQ? would mean ‘return
the current value of the transmit frequency’
2) From Target to Controller, the only permitted values are:
= (ASCII code 61)
? (ASCII code 63)
! (ASCII code 33)
* (ASCII code 42)
They have these meanings:
The ‘=’ code (target to controller) is used in two ways:
First, if the controller has sent a query code to a target (for example TFQ?,
meaning ‘what’s the Transmit frequency?’), the target would respond with
TFQ=xxx.xxxx, where xxx.xxxx represents the frequency in question.
B–4 Rev. 1.3
CDM-500 Closed Network Satellite Modem Remote Control
Second, if the controller sends an instruction to set a parameter to a particular
value, then, providing the value sent in the argument is valid, the target will
acknowledge the message by replying with TFQ= (with no message arguments).
The ? code (target to controller) is only used as follows:
If the controller sends an instruction to set a parameter to a particular value, then,
if the value sent in the argument is not valid, the target will acknowledge the
message by replying (for example) with TFQ? (with no message arguments).
This indicates that there was an error in the message sent by the controller.
The * code (target to controller) is only used as follows:
If the controller sends an instruction to set a parameter to a particular value, then,
if the value sent in the argument is valid, BUT the modem will not permit that
particular parameter to be changed at that time, the target will acknowledge the
message by replying (for example) with TFQ* (with no message arguments).
The ! code (target to controller) is only used as follows:
If the controller sends an instruction code which the target does not recognize,
the target will acknowledge the message by echoing the invalid instruction,
followed by the ! character with.
Example: XYZ!
B.5.5 Message Arguments
Arguments are not required for all messages. Arguments are ASCII codes for the
characters 0 to 9 (ASCII 48 to 57), period (ASCII 46) and comma (ASCII 44).
B.5.6 End Of Packet
Controller to Target: This is the ‘Carriage Return’ character (ASCII code 13)
Target to Controller: This is the two-character sequence ‘Carriage Return’, ‘Line Feed’.
(ASCII code 13, and code 10.)
Both indicate the valid termination of a packet.
Rev. 1.3 B–5
Remote Control CDM-500 Closed Network Satellite Modem
This page is intentionally blank.
B–6 Rev. 1.3
CDM-500 Closed Network Satellite Modem Remote Control
Parameter
Type
Tx Frequency TFQ= 8 bytes Command or Query.
Tx Data Rate TDR= 7 bytes
Tx
FEC Code
Rate
Tx
Modulation
Type
Tx Spectrum
Invert
Rev. 1.3 B–7
Command
(Instruction
Code and
qualifier)
TCR= 1 byte, value of
TMD= 1 byte, value
TSI= 1 byte, value of
Arguments
for Command
or Response to
Query
1,3 or 7
of 1 or 2
0 or 1
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Tx Frequency, 52 MHz to 88 MHz, (70 MHz band)
or 104 MHz to 176 MHz, (140 MHz band).
Resolution = 100Hz.
Example: TFQ=072.9876 (70 MHz option)
TFQ=148.0000 (140 MHz option)
Note: Querying ‘Options Fitted’ (using EID?) will
indicate if the unit has the 70 MHz or 140 MHz
synthesizer option fitted.
Command or Query.
Tx Data rate, in kbps, between 2.4 kbps and 512
kbps. Resolution = 1 bps.
Example: TDR=511.999 (which is 511.999 kbps)
Command or Query.
Tx FEC Code rate, where:
1 = Rate 1/2
3 = Rate 3/4
7 = Rate 7/8
All other codes invalid.
Example: TCR=1 (which is Rate 1/2)
Command or Query.
Tx Modulation type, where:
1 = BPSK,
2 = QPSK
All other codes invalid.
Example: TMD=2 (which is QPSK)
Command or Query.
Tx Spectrum Invert selection, where:
0 = Normal,
1 = Tx Spectrum Inverted
All other codes invalid.
Example:TSI=0 (which is normal)
Response to
Command (target to
controller)
TFQ= (message ok)
TFQ? (received ok,
but invalid arguments
found)
TFQ* (message ok,
but not permitted in
current mode)
TDR= (message ok)
TDR? (received ok,
but invalid arguments
found)
TFQ* (message ok,
but not permitted in
current mode)
TCR= (message ok)
TCR? (received ok,
but invalid argument
found)
TCR* (message ok,
but not permitted in
current mode)
TMD= (message ok)
TMD? (received ok,
but invalid argument
found)
TMD* (message ok,
but not permitted in
current mode)
TSI= (message ok)
TSI? (received ok,
but invalid arg.
found)
TSI* (message ok,
but not permitted in
current mode)
Query
(Instruction
Code and
qualifier)
TFQ? TFQ=xxx.xxxx
TDR? TDR=xxx.xxx
TCR? TCR=x (same
TMD? TM D=x (same
TSI? TSI=x (same
Response to
query (target
to controller)
(same format as
command
arguments)
(same format as
command
arguments)
format as
command
argument)
format as
command
argument)
format as
command
argument)
Remote Control CDM-500 Closed Network Satellite Modem
Parameter
Type
Tx Scrambler TSC= 1 byte, value of
Tx Power
Level
Tx Clock
Source
Tx Carrier
On/Off State
Rx Frequency RFQ= 8 bytes Command or Query.
Rx Data Rate RDR= 7 bytes Command or Query.
B–8 Rev. 1.3
Command
(Instruction
Code and
qualifier)
TPL= 4 bytes Command or Query.
TCK= 1 byte, value of
TXO= 1 byte, value of
Arguments
for Command
or Response to
Query
0 or 1
1,2 or 3
0, 1 or 2
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Command or Query.
Tx Scrambler state, where:
0 = Off
1 = On (V.35 in transparent mode, synchronous in
framed mode
All other codes invalid.
Example: TSC=1 (which is scrambler On)
Tx Output power level between 0 and -20 dBm
(minus sign assumed). Example: TPL=13.4 (which is
-13.4 dBm)
Command or Query.
Tx Clock source, where:
1 = Internal
2 = External
3 = Loop timed (use Rx satellite clock)
All other codes invalid.
Example: TCK=2 (which is External Clock)
Command or Query.
Tx Carrier On/Off state, where:
0 = Off due to front panel or rem. control command
1 = On
2 = Off due to ext H/W Tx Carrier Off command (not
a valid argument when used as a co mmand) All o ther
codes invalid.
Example: TXO=1 (which is Tx Carrier On)
Rx Frequency, 52 MHz to 88 MHz, (70 MHz band) or
104 MHz to 176 MHz (140 MHz band).
Resolution = 100 Hz.
Example: RFQ=143.4567 (which is 143.4567 MHz)
Note: Querying ‘Options Fitted’ (using EID?) will
indicate if the unit has the 70 MHz or 140 MHz
synthesizer option fitted.
Rx Data rate, in bps, between 2.4 kbps and 512
kbps. Resolution = 1 bps.
Example: RDR=002.400 (which is 2.4 kbps)
Response to
Command (target to
controller)
TSC= (message ok)
TSC? (received ok,
but invalid argument
found)
TSQ* (message ok,
but not permitted in
current mode)
TPL= (message ok)
TPL? (received ok,
but invalid arguments
found)
TPL* (message ok,
but not permitted in
current mode)
TCK= (message ok)
TCK? (received ok,
but invalid argument
found)
TCK* (message ok,
but not permitted in
current mode)
TXO= (message ok)
TXO? (received ok,
but invalid argument
found)
TXO* (message ok,
but not permitted in
current mode)
RFQ= (message ok)
RFQ? (received ok,
but invalid arguments
found)
RFQ* (message ok,
but not permitted in
current mode)
RDR= (message ok)
RDR? (received ok,
but invalid arguments
found)
RDR* (message ok,
but not permitted in
current mode
Query
(Instruction
Code and
qualifier)
TSC? TSCS=x (same
TPL? TPL=xx.x
TCK? TCK=x (same
TXO? TXO=x (Note
RFQ? RFQ=xxx.xxxx
RDR? RDR=xxx.xxx
Response to
query (target
to controller)
format as
command
argument)
(same format as
command
arguments)
format as
command
argument)
that 2 is not a
valid argument
when used as a
command)
(same format as
command
arguments)
(same format as
command
arguments)
CDM-500 Closed Network Satellite Modem Remote Control
Parameter
Type
Rx FEC Code
Rate
Rx
Modulation
Type
Rx Spectrum
Invert
Rx
Descrambler
Rx Demod
Acq Sweep
Width
Rx Clock
Mode
Rev. 1.3 B–9
Command
(Instruction
Code and
qualifier)
RCR= 1 byte, value of
RMD= 1 byte, value of
RSI= 1 byte, value of
RDS= 1 byte, value of
RSW= 2 bytes,
RCK= 1 byte, value of
Arguments
for Command
or Response to
Query
1,3 or 7
1or 2
0 or 1
0 or 1
numerical
0 or 1
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Command or Query.
Rx FEC Code rate, where:
1 = Rate 1/2,
3 = Rate 3/4,
7 = Rate 7/8
All other codes invalid.
Example: RCR=1 (which is Rate 1/2)
Command or Query
Rx Modulation type, where:
1 = BPSK
2 = QPSK
All other codes invalid.
Example: RMD=1 (BPSK)
Command or Query.
Rx Spectrum Invert selection, where:
0 = Normal
1 = Rx Spectrum Inverted
All other codes invalid.
Command or Query.
Rx De-scrambler state, where:
0 = Off
1 = On (V.35 in unframed mode, synchronous in
framed mode
All other codes invalid.
Example: RDS=1 (which is de-scrambler On)
Command or Query.
Rx ± acquisition sweep range of demodulator, in
kHz, ranging from ± 1 kHz to ± 30 kHz.
Example: RSW=09 (which is 9 kHz)
Rx Clock mode, where:
Command or Query.
0 = Buffer disabled
1 = Buffer enabled
All other codes invalid.
Example: RCK=0 (which is buffer disable)
Response to
Command (target to
controller)
RCR= (message ok)
RCR? (received ok,
but invalid argument
found)
RCR* (message ok,
but not permitted in
current mode
RMD= (message ok)
RMD? (received ok
but invalid argument
found)
RMD* (message ok,
but not permitted in
current mode)
RSI= (message ok)
RSI? (received ok,
but invalid argument
found)
RSI* (message ok,
but not permitted in
current mode)
RDS= (message ok)
RDS? (received ok,
but invalid argument
found)
RDS* (message ok,
but not permitted in
current mode)
RSW= (message ok)
RSW? (received ok,
but invalid arguments
found)
RSW* (message ok,
but not permitted in
current mode)
RCK= (message ok)
RCK? (received ok,
but invalid argument
found)
RCK* (message ok,
but not permitted in
current mode)
Query
(Instruction
Code and
qualifier)
RCR? RCR=x
RMD? RMD=x
RSI? RSI=x
RDS? RDS=x
RSW? RSW=xx (same
RCK? RCK=x
Response to
query (target
to controller)
(same format as
command
argument)
(same format as
command
argument)
(same format as
command
argument)
(same format as
command
argument)
format as
command
arguments)
(same format as
command
argument)
Remote Control CDM-500 Closed Network Satellite Modem
Parameter
Type
Eb/No Alarm
Point
Rx Buffer
Size
Unit Interface
Type
Unit Framing
Mode
Unit Test
Mode
Unit IF
Impedance
B–10 Rev. 1.3
Command
(Instruction
Code and
qualifier)
EBA= 4 bytes,
RBS= 1 byte, value of
ITF= 1 byte, value of
FRM= 1 byte, value of
TST= 1 byte, value of
IMP= 1 byte, value of
Arguments
for Command
or Response to
Query
numerical
1,2,3,4 or 5
1,2 or 3
0 or 1
0,1,2,3,4 or 5
5 or 7
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Command or Query.
Eb/No alarm point, with a range of Eb/No between 2
and 16 dB. Resolution 0.1 dB.
Example: EBA=12.3 (which is Eb/No = 12.3 dB)
Command or Query.
Rx buffer size, where:
1 = +/- 256 bits
2 = +/- 512 bits
3 = +/- 1024 bits
4 = +/- 2048 bits
5 = +/- 4096 bits
Command or Query.
Terrestrial interface type, where:
1 = RS422/EIA530 DCE,
2 = V.35 DCE
3 = RS232 (sync).
All other codes invalid. Example: ITF=2 (V.35)
Command or Query.
Unit operating mode, where
0 = Unframed - transparent (distant-end M&C not
possible)
1 = Framed (EDMAC distant-end M&C possible)
Example: FRM=1 (which is framed)
0 = Normal
1 = IF loopback
2 = Digital loopback
3 = I/O loopback
4 = Tx CW
5 = Tx Alternating 1,0 pattern
All other codes invalid.
Example TST=4 (which is transmit CW)
Command or Query.
IF interface impedance, where:
5 = 50 ohms
7 = 75 ohms
All other codes invalid. Example IMP=7 ( 75 ohms)
Response to
Command (target to
controller)
EBA= (message ok)
EBA? (received ok,
but invalid arguments
found)
RBS= (message ok)
RBS? (received ok,
but invalid argument
found)
RBS* (message ok,
but not permitted in
current mode)
ITF= (message ok)
ITF? (received ok,
but invalid args
found)
ITF* (message ok,
but argument) not
permitted in current
mode)
FRM= (message ok)
FRM? (received ok,
but invalid argument
found)
FRM* (message ok,
but not permitted in
current mode)
TST= (message ok)
TST? (received ok,
but invalid argument
found)
TST* (message ok,
but not permitted in
current mode)
IMP= (message ok)
IMP? (received ok,
but invalid argument
found)
Query
(Instruction
Code and
qualifier)
EBA? EBA=xx.x
RBS? RBS=x
ITF? ITF=x (same
FRM? FRM=x (same
TST? TST=x (same
IMP? IMP=x (same
Response to
query (target
to controller)
(same format as
command
arguments)
(same format as
command
argument)
format as
command
format as
command
argument)
format as
command
argument)
format as
command
argument)
CDM-500 Closed Network Satellite Modem Remote Control
Parameter
Type
Unit Alarm
Mask
EDMAC
Slave Address
Circuit ID
string
Outdoor Unit
Comms
Rev. 1.3 B–11
Command
(Instruction
Code and
qualifier)
MSK= 5 bytes, each
ESA= 4 bytes,
CID= 24 bytes,
ODU= 1 byte, of 0 or
Arguments
for Command
or Response to
Query
with a value of
0 or 1
numerical
ASCII
1 value
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Command or Query.
Alarm mask conditions, in the form abcde, where:
a = mask Tx AIS alarm, b = mask Rx AGC alarm
c = mask buffer alarms, d = mask Rx AIS alarm
e = mask Eb/No alarm
Setting any of these bytes to 0 unmasks alarm, setting
to 1 masks them. Example: MSK=01011
Command or Query.
EDMAC Slave Address - sets the range of addresses
of distant-end units (modems or transceivers) which
this unit will forward messages for. Only values
which are integer multiples of ten are permitted.
(0010, 0020, 0030, 0040 etc.)
Example: ESA=0890
Important Note: Setting the value of the EDMAC
Slave Address to 0000 disables this function. Setting
a valid address here will automatically define the
unit as being an EDM AC Master.
This command is only valid for an EDMAC master.
When used as a Query, it may be sent to an EDMAC
slave, which will respond with the appropriate
address.
Command or Query.
Sets or queries the user-defined Circuit ID string,
which is a fixed length of 24 characters.
Valid characters include:
Space ( ) * + - , . / 0-9 and A-Z
Command or Query.
Enables or disabl es communication, via an FSK serial
link, with a Comtech Transceiver (Outdoor unit).
0 = disabled
1 = enabled
Example: ODU=0
Response to
Command (target to
controller)
MSK= (message ok)
MSK? (received ok,
but invalid arguments
found)
MSK* (message ok,
but not permitted in
current mode)
ESA= (message ok)
ESA? (received ok,
but invalid arguments
found) ESA*
(message ok, but not
permitted in current
mode – for example
if ESA= is sent to a
distant-end slave
unit)
CID= (message ok)
CID? (received ok,
but invalid arguments
found)
ODU= (message ok)
ODU? (received ok,
but invalid arguments
found) ODU*
(message ok, but not
permitted in current
mode
Query
(Instruction
Code and
qualifier)
MSK? MSK=abcde
ESA? ESA=xxxx
CID? CID=xxxxxxxx
ODU? ODU=x (same
Response to
query (target
to controller)
(same format as
command
arguments)
(same format as
command
arguments)
xxxxxxxxxxxx
xxx (same
format as
command
arguments)
format as
command
arguments)
Remote Control CDM-500 Closed Network Satellite Modem
Parameter
Type
Global
Configuration
Command
(Instruction
Code and
qualifier)
MGC= 74 bytes, with
Arguments
for Command
or Response to
Query
numerical
entries, fixed
value entries,
and delimiters
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Command or Query.
Global configuration of unit, in the form: FFF.FFFF
DDD.DDDRMVSPP.PCXfff.ffffddd.dddrmvsww
ctt.tbIOTZAAAAAUEEEEYYYYYYYY, where:
F = Tx Frequency - same as TFQ= (8 bytes)
D = Tx Data Rate - same as TDR= (7 bytes)
R = Tx FEC Code Rate - same as TCR= (1 byte)
M = Tx Modulation - same as TMD= (1 byte)
V = Tx Spectrum Invert - same as TSI= (1 byte)
S = Tx Scrambler State - same as TSC= (1 byte)
P = Tx Power Level - same a s TPL= (4 bytes)
C = Tx Clock Source - same as TCK= (1 byte)
X = Tx Carrier Status - same as TXO= (1 byte)
f = Rx Frequency - same as RFQ= (8 bytes)
d = Rx Data Rate - same as RDR= (7 bytes)
r = Rx FEC Code Rate - same as RCR= (1 byte)
m = Rx Modulation - same as RMD= (1 byte)
v = Rx Spectrum Invert - same as RSI= (1 byte)
s = Rx De-scrambler - same as RDS= (1 byte)
w= Rx Sweep Width - same as RSW= (2 bytes)
c = Rx Clock Mode - same as RCM= (1 byte)
t = Eb/No Alarm Point - same as EBA= (4 bytes)
b = Rx Buffer Size - same as RBS= (1 byte)
I = Unit Interface Type - same as ITF= (1 byte)
O =Unit Framing Mode - same as FRM= (1 byte)
T = Unit Tes t Mode - same as TST= (1 byte)
Z = Unit IF Impedance - same as IMP= (1 byte)
A = Alarm Mask - same as MSK= (5 bytes)
U= ODU Comms - same as ODU= (1 byte)
E= EDMAC Slave address - same as ESA= (4 bytes)
Y = expansion (8 bytes), reserved - set to ‘0'
Example:
MGC=074.5678064.000720112.720082.6543
128.000320116109.812111000001023600000000
Response to
Command (target to
controller)
MGC= (message ok)
MGC? (received ok,
but invalid arguments
found)
Query
(Instruction
Code and
qualifier)
MGC? MGC=F F F .F
Response to
query (target
to controller)
F F F D D D .
DDDRMV
S P P .P C X f f
f .f f f f d d d .
d d d r m v s w
w c t t .t b I O
TZAAAAA
U E E E E Y Y
Y
Y Y Y Y Y
(same format
as command
arguments)
B–12 Rev. 1.3
CDM-500 Closed Network Satellite Modem Remote Control
Parameter
Type
Config Store CST= 1 byte,
Config Load CLD= 1 byte,
Re-center
Buffer
Force 1:1
Switch
10dB
attenuator set
Rev. 1.3 B–13
Command
(Instruction
Code and
qualifier)
RCB= None Command only.
FSW= None Command only.
ATS= 1 byte, value of
Arguments
for Command
or Response to
Query
numerical, 0 to
9
numerical, 0 to
9
0 or 1
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Forces the unit to st ore the current modem
configuration in Configuration Memory location
defined by the one byte argument (0 to 9).
Example CST=4 (Store current config in location 4)
WARNING: Use with caution! If the location already
contains data it will be automatically overwritten. If
in doubt, query the location first.
Command only.
Forces the unit to retrieve the Configuration Memory
location defined by the one byte argument (0 to 9)
and to re-program the unit with that stored
configuration.
Forces the unit to re-center the receive
plesiochronous/doppler buffer. This command takes
no arguments.
Forces the unit to toggle the Unit Fail relay to the
‘fail’ state for approx 500ms. If the unit is a 1:1 pair,
and it is currently the ‘On Line’ unit, this will force a
switchover, so the unit will then be in ‘Standby’
mode. The command is always executed by the unit,
regardless of whether it is stand-alone, in a 1:1 pair,
or part of a 1:N system.
This command takes no arguments.
FACTORY USE ONLY
Modulator output 10dB attenuator setting, where
0 = no attenuation
1 = 10 dB attenuation
Example: ATS=0
(Used for power-level calibration)
Response to
Command (target to
controller)
CST= (message ok)
CST? (received ok,
but invalid arguments
found)
CLD= (message ok)
CLD? (message
received ok, but
either an invalid
argument was found,
or the requested
location does not
contain a valid
configuration)
RCB= (message ok) N/A N/A
FSW= (message ok) N/A N/A
ATS= (message ok)
ATS? (received ok,
but invalid arguments
found) ATS*
(message ok, but not
permitted in current
mode
Query
(Instruction
Code and
qualifier)
CST?n where
n is 0 to 9
CST?0, or
CST?1, or
CST?2, or
CST?3, or
CST?4, or
CST?5, or
CST?6, or
CST?7, or
CST?8, or
CST?9
N/A N/A
ATS? ATS=n
Response to
query (target
to controller)
Return the same
format as the
MGC with the
form: CST= for
a valid config,
and CST*
where no valid
config is found
in that n
where n is 0 or
1
Remote Control CDM-500 Closed Network Satellite Modem
Parameter
Type
Power level
DAC set
Write
EEPROM
Value
Read
EEPROM
Value
Set RTC Date DAY= 6 bytes,
Set RTC Time TIM= 6 bytes,
Clear All
Stored Events
B–14 Rev. 1.3
Command
(Instruction
Code and
qualifier)
DAC= 4 bytes,
EWR= 7 bytes Command only. FACTORY USE ONLY
N/A 3 bytes Query only. FACTORY USE ONLY
CAE= None Command only
Arguments
for Command
or Response to
Query
numerical
numerical
numerical
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
FACTORY USE ONLY
Modulator power output DAC setting. An argument
between 0000 and 4095 is required
Example: DAC=1287
(Used for power-level calibration)
A command in the form ddd,aaa, where ddd is a
single byte data value between 0 and 255, and aaa is a
starting address (in the range 0 - 127) within the serial
EEPROM, where the data is to be written.
Example: EWR=127,104 means write the value 127
starting at address location 104.
(Used for power-level cal, amongst other things)
A query in the form aaa where aaa is a starting bit
address (in the range 0 - 127) within the modem’s
serial EEPROM, requ est ing that the byte stored at th at
location be returned.
Example: ERD?063 returns the value of the byte
stored at location 063.
(Used for power-level cal, amongst other things)
Command or query
A command in the form ddmmyy, where; dd = day of
the month, between 01 and 31, mm = month of the
year, between 01 and 12 and yy = year, between 97
and 96 (1997 to 2000, then 2000 to 2096)
Example: DAY=240457 would be April 24, 2057
Command or query
A command in the form hhmmss, indicating the time
from midnight, where hh = hours, between 00 and23;
mm = minutes, between 00 and 59, and ss = seconds,
between 00 and 59
Example: TIM=231259 would be 23 hours, 12
minutes and 59 seconds from midnight.
Instructs the unit t o clear all Stored Events
This command takes no arguments.
Response to
Command (target to
controller)
DAC= (message ok)
DAC? (received ok,
but invalid arguments
found)
DAC* (message ok,
but not permitted in
current mode.
EWR= (message ok)
EWR? (received ok,
but invalid arguments
found)
EWR* (message ok,
but not permitted in
current mode
N/A ERD? ERD=xxx
DAY= (message ok)
DAY? (received ok,
but invalid arguments
found)
DAY* (message ok,
but not permitted in
current mode
TIM= (message ok)
TIM? (received ok,
but invalid arguments
found)
TIM* (message ok,
but not permitted in
current mode
CAE= (message ok) N/A N/A
Query
(Instruction
Code and
qualifier)
DAC? DAC=xxxx
N/A N/A
DAY? DAY=xxxxxx
TIM? TIM=xxxxxx
Response to
query (target
to controller)
where xxxx is a
value between
0000 and 4095
where xxx is a
value between 0
and 255
(same format as
command
arguments)
(same format as
command
arguments)
CDM-500 Closed Network Satellite Modem Remote Control
Parameter
Type
Retrieve next
5 unread
Stored Events
Retrieve
Number of
unread Stored
Events
Rx Eb/No N/A 4 bytes,
Rx Freq
Offset
Rev. 1.3 B–15
Command
(Instruction
Code and
qualifier)
N/A 75 bytes Query only
N/A 2 bytes,
N/A 5 bytes, 1st , +
Arguments
for Command
or Response to
Query
numerical
numerical
or -, next
4bytes
numerical
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Unit returns the oldest 5 Stored Events which have
not yet been read over the remote cont rol. Reply
format: {CR}Sub-body{CR}Sub-body{CR}Subbody{CR}Sub-body{CR}Sub-body, where Subbody= ABCmmddyyhhmmss,
A being the fault/clear indicator.
F=Fault
C=Clear
I=Info
B being the fault type where:
1=Unit
2=Rx Traffic
3=Tx Traffic
4=Power on/off, or log cleared
and C being the fault code, as defined under the ‘FLT’
message table entry, except Info codes, which are:
0=power off, 1=power on, 2=log cleared, 3=global
config change, and 4= redundancy config change. If
there are no new events, the unit replies with RNE? If
there are less than 5 events to be retrieved, the
remaining positions are padded with zeros.
Query onl y.
Unit returns the number of Stored Events which
remain unread, in the form xx. Note: This means
unread over the remote con t rol - viewing the stored
events from the front panel of the modem does not
affect this value. Example reply: NUE=98
Query onl y.
Unit returns the value of Ebi/No, between 2 and
16dB. Resolution 0.1 dB. Returns 99.9 if demod is
unlocked.
Example: EBN=12.3 (which is Eb/No = 12.3 dB) For
values greater than 16.0 dB, the reply will be
EBN=+16.
Query onl y.
Unit returns the value of freq. offset of the carrier
being demodulated. Values range from ±0 to ± 30
description for kHz, 100 Hz resolution.Example:
RFO=+023 (offset is +2.3 kHz) Returns 9999 if
demod unlocked.
Response to
Command (target to
controller)
N/A RNE? RNE={CR}AB
N/A NUE? NUE=xx
N/A EBN? EBN=xx.x
N/A
Query
(Instruction
Code and
qualifier)
RFO?
Response to
query (target
to controller)
C
mmddyyhhm
mss{CR}ABCm
mddyyhhmms
s{CR}ABCmm
ddyyhhmmss{
CR}ABCmmdd
yyhhmmss{CR
}ABCmmddyy
hhmmss
(see description
for details of
arguments)
(see description
for details of
arguments)
(see description
for details of
arguments)
RFO=nxx.x
(see details of
arguments)
Remote Control CDM-500 Closed Network Satellite Modem
Parameter
Type
Buffer Fill
State
Rx BER N/A 5 bytes Query only.
Redundancy
State
Local/Remote
Status
Serial Number SNO= 4 bytes
Software
Revision
Equipment ID N/A 6 bytes,
B–16 Rev. 1.3
Command
(Instruction
Code and
qualifier)
N/A 2 bytes,
N/ A 1 byte, value of
N/A 1 byte, value of
N/A 4 bytes,
Arguments
for Command
or Response to
Query
numerical
0 or 1
0 or 1
numerical
numerical
numerical
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Query onl y.
Unit returns the value of the buffer fill state. Values
range from 1 to 99% .Example: BFS=33 (buffer fill
state is 33%) Returns 00 if demod unlocked.
Unit returns the value of the estimated corrected BER
in the form a.b x 10exp-c. Fist and second bytes are
value, 3rd and 4th bytes are the exponent.
Returns99999 if demod is unlocked.
Example: BER=4.8E3 (BER is 4.8 x 10-3)
Query onl y.
Returns the redundancy state of the unit, where:
0 = Off Line (forced into standby by 1:N or 1:1
Switch)
1= On Line (normal).
All other codes invalid.
Example: RED=1 (On Line)
Query onl y.
Returns the local/remote stat us of the unit, where:
0 = local
1= remote
Example: LRS=1 (unit is in remote mode)
Command portion is FACTORY USE ONLY. Used
to set or Query the units 4 digit serial number.
0000 to 9999 Unit returns its S/N, in the form xxxx.
Example: SNO=1765
Query onl y.
Unit returns the value of internal software revision
installed in the unit, in the form x.xx
Example: SWR=1.03 (Ver 1.03)
Query onl y.
Unit returns information concerning the equipment
identification, and the options fitted, in the form
aaaabc, where:
aaaa defines the Modem model number. E xample:
0500 is CDM-500
b defines the IF band, with 1 = 70MHz, 2 = 140MHz
c defines RX only, with 1 = RX/TX, 2 = RX only
Ex: EID=050012 (CDM-500, 70 MHz band, RX
only)
Response to
Command (target to
controller)
N/A BFS? BFS=xx (see
N/A BER? BER=a.bEc
N/A RED? RED=x
N/A LRS? LRS=x
SNO= (message ok) SNO? SNO=xxxx
N/A SWR? SWR=x.xx
N/A EID? EID=aaaabc
Query
(Instruction
Code and
qualifier)
Response to
query (target
to controller)
description for
details of
arguments)
(see description
for details of
arguments)
(see description
for details of
arguments)
(see description
for details of
arguments)
(see description
for details of
arguments)
(see description
for details of
arguments)
(see description
for details of
arguments)
CDM-500 Closed Network Satellite Modem Remote Control
Parameter
Type
Faults and
Status
Command
(Instruction
Code and
qualifier)
N/A 5 bytes, first 3
Arguments
for Command
or Response to
Query
bytes
numerical4th
and 5th bytes,
value of 0 or 1
Description of arguments
(note that all arguments are ASCII numeric codes,
that is, ASCII codes between 48 and 57)
Query onl y.
Unit returns the current fault and status codes for the
Unit (hardware), Tx Traffic and Rx Traffic, in the
form abcde, where:
a = Unit fault status, b = Tx Traffic status,
c = Rx Traffic Status, d = Change in F ault Status
since last poll (0 = none, 1 = change), e = Change in
Unit Configuration since last poll (0 = none, 1 =
change)
Unit faults:
0 = No faults
1 = Power supply fault, 5 volts
2 = Power supply fault , 12 volts
3 = Power supply fault, -5 volts
4 = Power supply fault, 18 volts
5 = Power supply fault, -12 volts
6 = FPGA load fail
7 = Tx synthesiser lock
8 = Rx synthesiser
9 = Power cal Checksum error
Tx Traffic status:
0 = Tx traffic OK
1 = No clock from terrestrial interface
2 = Tx FIFO slip
3 = AIS detected on incoming data
Rx Traffic status:
0 = Rx Traffic OK
1 = Demodulator unlocked
2 = AGC Alarm - signal level too high
3 = Frame sync lost (EDMAC mode only)
4 = Buffer Underflow
5 = Buffer Overflo w
6 = AIS detected on incoming data
7 = Eb/No threshold exceeded
Response to
Command (target to
controller)
N/A FLT? FLT=abcde
Query
(Instruction
Code and
qualifier)
Response to
query (target
to controller)
(see description
for details of
arguments
Rev. 1.3 B–17
Remote Control CDM-500 Closed Network Satellite Modem
This page has been intentionally left blank.
B–18 Rev. 1.3
- A -
Address................................................... B–4
Alarms Connector .................................. 5–2
Approvals............................................... A–3
Auxiliary Serial Connector .................... 5–3
- B -
Basic Protocol ........................................ B–2
Buffer Disabled...................................... 7–2
Buffer Enabled, Rx<>Tx........................ 7–2
Buffer Enabled, Rx=Tx.......................... 7–2
- C -
CONFIG) FRAME (Framing Mode) ..... 6–12
CONFIG) IMPED (IF impedance)......... 6–18
CONFIG) INTFC (Interface) ................. 6–14
CONFIG) MASK (Alarm mask)........... 6–16
CONFIG) REMCONT (Remote control)6–14
CONFIG) RX (Receive)........................ 6–8
CONFIG) TX (Transmit)...................... 6–5
CONFIG, FRAME) FRAMED.............. 6–12
CONFIG, FRAME) TRANSPARENT .. 6–12
CONFIG, MASK) AGC........................ 6–16
CONFIG, MASK) BUF-SLIP................ 6–17
CONFIG, MASK) Eb/No....................... 6–17
CONFIG, MASK) RX-AIS.................... 6–17
CONFIG, MASK) TX-AIS.................... 6–18
CONFIG, RX) ACQ.............................. 6–10
CONFIG, RX) DATA (Data Rate) ....... 6–9
CONFIG, RX) DESCRAM................... 6–10
CONFIG, RX) FEC............................... 6–9
Index
I
CONFIG, RX) FRQ (Frequency)...........6–9
CONFIG, RX) MOD (Modulation).......6–8
CONFIG, RX) BUF (Buffer size)...........6–11
CONFIG, RX) CLK (Clocking)..............6–10
CONFIG, RX) Eb/No (Eb/No Alarm)....6–12
CONFIG, RX) RSI .................................6–11
CONFIG, TX) CLK (Clocking).............6–7
CONFIG, TX) DATA (Data Rate) ........6–5
CONFIG, TX) FEC................................6–6
CONFIG, TX) FREQ (Frequency)........6–5
CONFIG, TX) MOD (Modulation).......6–5
CONFIG, TX) ON/OFF.........................6–6
CONFIG, TX) PWR (Power) ................6–7
CONFIG, TX) SCRAM (Scrambling)...6–7
CONFIG, TX) TSI.................................6–8
CONFIG:.................................................6–4
Configuration..........................................2–2
Connect External Cables.........................2–2
Connector Pinouts...................................5–1
- D -
Data Connector.......................................5–1
Data Interfaces........................................A–3
Demodulator ...........................................A–2
Description..............................................6–1
Disclaimer...............................................viii
- E -
EIA-232...................................................B–2
EIA-485...................................................B–1
Electrical Safety......................................vi
EMC (Electromagnetic Compatibility)...vii
Rev. 1.3 i–1
Index CDM-500 Satellite Modem
End Of Packet ........................................ B–6
Environmental........................................ vi
Exclusive Remedies............................... viii
External Clock........................................ 7–1
- F -
Front Panel............................................. 4–1
Functional Description........................... 3–1
Fuses....................................................... vi
- I -
INFO (Information)................................ 6–19
INFO) BUFF (Buffer information)........ 6–21
INFO) EDMAC...................................... 6–21
INFO) ID (Circuit ID)............................ 6–20
INFO) MASK......................................... 6–22
INFO) MISC........................................... 6–22
INFO) REMCONT................................. 6–21
INFO) RX (Receive information).......... 6–20
INFO) TX (Transmit information)......... 6–20
Installation.............................................. vii
Instruction Code Qualifier ..................... B–4
Instruction Code..................................... B–4
Internal Clock......................................... 7–1
Introduction............................................ 1–1
Introduction............................................ B–1
- L -
Limitations of Warranty......................... viii
Loop-Timed............................................ 7–2
- M -
M&C Connection................................... 8–2
Menu Trees ............................................ 6–2
Message Arguments............................... B–5
Miscellaneous......................................... A–3
Modulator............................................... A–1
MON, ALARMS) RECEIVE................. 6–23
MON, ALARMS) TRANSMIT............. 6–23
MON, ALARMS) UNIT (Unit alarms).. 6–23
MON, EVENTS) VIEW ........................ 6–24
MONIT (Monitor).................................. 6–22
MONIT) ALARMS................................ 6–23
MONIT) STORED EVENTS................. 6–24
Mounting................................................ 2–1
- O -
Opening Screen...................................... 6–2
- P -
Packet Structure......................................B–3
- R -
Rear Panel...............................................4–3
Receive Clocking....................................7–2
Remote Control Connector.....................5–2
Reporting Comments or Suggestions
Concerning this Manual..........................vii
- S -
SAFETY NOTICES................................vi
Select Internal IF Loop...........................2–2
SELECT..................................................6–4
Setup Summary.......................................8–3
Start Of Packet........................................B–3
STO/LD) LOAD.....................................6–26
STORE/LD (Store/Load)........................6–25
STORE/LD) STORE ..............................6–26
- T -
Telecommunications Terminal Equipment
Directive..................................................vii
TEST.......................................................6–18
Theory Of Operation...............................8–1
Transmit Clocking ..................................7–1
- U -
Unpacking...............................................2–1
UTIL (Utility).........................................6–27
UTIL) DISPLAY (Display brightness)...6–28
UTIL) ID (Circuit ID).............................6–28
UTIL) MAN-1:1 .....................................6–28
UTIL) RECENTER-BUF .......................6–28
UTIL) SET-RTC (Set real-time clock)...6–27
- W -
Warranty Policy......................................viii
- X -
X.21 Notes ..............................................7–2
i–2 Rev. 1.3
METRIC CONVERSIONS
Units of Length
Unit
1 centimeter — 0.3937 0.03281 0.01094
1 inch 2.540 — 0.08333 0.2778
1 foot 30.480 12.0 — 0.3333
1 yard 91.44 36.0 3.0 —
Centimeter
Inch
Foot
Yard
Mile
6.214 x 10
1.578 x 10
1.893 x 10
5.679 x 10
Meter
-6
-5
-4
-4
0.01 — —
0.254 — 25.4
0.3048 — —
0.9144 — —
Kilometer Millimeter
1 meter 100.0 39. 37 3.281 1.094
1 mile
1 mm — 0.03937 — — — — — —
1 kilometer — — — — 0.621 — — —
1.609 x 10
5
6.336 x 104 5.280 x 103 1.760 x 103
6.214 x 10
-4
—
— — —
1.609 x 103
1.609 —
Temperature Conversions
Ounce
Troy
Formulas
C = (F - 32) * 0.555
F = (C * 1.8) + 32
Pound
Avoir.
Pound
Troy
Kilogram
Unit
32° Fahrenheit
212° Fahrenheit
-459.6° Fahrenheit
°°°°
Fahrenheit
—
—
—
°°°°
Centigrade
0
(water freezes)
100
(water boils)
273.1
(absolute 0)
Units of Weight
Unit
1 gram — 0.03527 0.03215 0.002205 0.002679 0.001
Gram
Ounce
Avoirdupois
1 oz. avoir. 28.35 — 0.9115 0.0625 0.07595 0.02835
1 oz. troy 31.10 1.097 — 0.06857 0.08333 0.03110
1 lb. avoir. 453.6 16.0 14.58 — 1.215 0.4536
1 lb. Troy 373.2 13.17 12.0 0.8229 — 0.3732
1 kilogram
1.0 x 10
3
35.27 32.15 2.205 2.679 —
2114
WEST 7TH STREET TEMPE ARIZONA
85281
480 • 333 • 2200
480 • 333
• 2161
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