Comtech EF Data CRS-200 User Manual
COMTECH EFData CORPORATION
CRS-200 REDUNDANCY SWITCH
OPERATIONS MANUAL
CONTENTS
1 SAFETY NOTICES 1
1.1 ELECTRICAL SAFETY 1
1.2 TELECOMMUNICATIONS TERMINAL
EQUIPMENT DIRECTIVE 2
1.3 EMC (ELECTROMAGNETIC COMPATIBILITY) 2
2 DESIGN PHILOSOPHY 4
3 CRS-200 OVERVIEW 5
4 PHYSICAL DESCRIPTION 7
4.1 FRONT PANEL 7
4.2 REAR PANEL 8
5 FUNCTIONAL DESCRIPTION 12
6 CONNECTOR PINOUTS 16
6.1 DATA CONNECTOR 16
6.2 SYSTEM ALARMS CONNECTOR 17
6.3 IF SWITCH CONTROL CONNECTOR 18
6.4 REMOTE CONTROL CONNECTOR 18
7 INSTALLATION 19
7.1 UNPACKING 19
7.2 MOUNTING 19
7.3 CONFIGURATION 19
8 SETUP GUIDE 20
8.1 25-PIN DATA CABLES 20
8.2 INITIAL CRS-200 SETUP 22
8.3 IF CABLES AND TRANSPONDER SWITCH 23
8.4 ADDITIONAL SWITCH CONFIGURATION 26
9 FRONT PANEL OPERATION 27
9.1 DESCRIPTION 27
9.2 MENU TREE 28
10 FLASH UPGRADING 40
11 SUMMARY OF SPECIFICATIONS 41
12 REMOTE CONTROL 43
12.1 INTRODUCTION 43
12.2 RS485 43
12.3 RS232 44
12.4 BASIC PROTOCOL 44
13 CABLE DRAWINGS 54
CRS-200 COMTECH COMMUNICATIONS CORPORATION
IMPORTANT INFORMATION - PLEASE READ BEFORE
INSTALLATION AND USE
1 SAFETY NOTICES
1.1 ELECTRICAL SAFETY
The CRS-200 Redundancy Switch 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:
1.1.1 FUSES
The CRS-200 is fitted with two fuses for each of its two power supply units - 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.
1.1.2 ENVIRONMENTAL
The CRS-200 must not be operated in an environment where the unit is exposed to
extremes of temperature outside the ambient range 0 to 50 C, precipitation,
condensation, or humid atmospheres above 95% RH, altitudes (un-pressurized)
greater than 2000 meters, excessive dust or vibration, flammable gases, corrosive
or explosive atmospheres.
0
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Operation in vehicles or other transportable installations that 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.
1.1.3 INSTALLATION
The installation and connection to the line supply must be made in compliance to
local or national wiring codes and regulations.
The CRS-200 is designed for connection to a power system that has separate ground,
line and neutral conductors. The equipment is not designed for connection to power
system that has no direct connection to ground.
The CRS-200 is shipped with line inlet cables suitable for use in the country of
operation. If it is necessary to replace this cable, ensure the replacement has an
equivalent specification. Examples of acceptable ratings for the cable include HAR,
BASEC and HOXXX-X. Examples of acceptable connector ratings include VDE, NFUSE, UL, CSA, OVE, CEBEC, NEMKO, DEMKO, BS1636A, BSI, SETI, IMQ, KEMAKEUR and SEV.
1.2 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.
1.3 EMC (ELECTROMAGNETIC COMPATIBILITY)
The CRS-200 Redundancy Switch 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 Redundancy Switch continues to comply with these standards, observe the
following instructions:
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All 'D' type connectors attached to the plug-in interface cards must have back-shells
that 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.
All plug-in interface cards must be secured tightly to the back panel by the built-in
captive screws. Blank panels must be used on all un-used Traffic Modem Interface
slots.
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.
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2 DESIGN PHILOSOPHY
Why use a Redundancy Switch?
There is only one answer to this question – to automatically protect satellite traffic circuits
against failures in modem equipment, and to hence improve the availability of those circuits.
In order for the Redundancy Switch to carry out its mission, it must be inherently more
reliable than the equipment it is protecting. If it is not, then it is a waste of time and
money installing it in the first place. There are therefore several key design considerations:
! The design should be electrically and mechanically as simple as possible. The
minimum number of electrical components should be used.
! Major elements should be modular, and if a failure in a module should occur, it
should be capable of being replaced without any disruption of normal traffic circuits.
! Single point failures should be avoided. This is particularly true of the Power Supply.
! Cabling should be kept to a minimum. Cables are a traditional source of problems.
! The user interface should be as simple as possible – the software needs to be
intuitive, and easy to understand.
! Un-necessary switching should be avoided. It wastes time and accomplishes nothing.
COMTECH’S PHILOSOPHY:
SIMPLE = RELIABLE
The CRS-200 embodies all of these design considerations – the emphasis is on simplicity,
without sacrificing functionality.
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3 CRS-200 OVERVIEW
WARNING
Please note that the CRS-200 has been designed specifically as an
accessory product for the Comtech CDM-500, CDM-550 and
CDM-550T Modems,
and should not be used with any other manufacturer’s equipment.
The CRS-200 1:10 Redundancy Switch, for use with the CDM-500, CDM-550 and CDM550T Modems, provides fully automatic protection of traffic circuits in the case of equipment
failure, and is intended for hub applications.
If all Modems within a group are connected to the same up/downconverter, no external IF
switching is required. However, where operation with more than one up/downconverter is
required, the user may add the CRS-280 IF Switch, which permits connection to as many
converters as there are Traffic Modems.
The CRS-200 will support all of the interface types available on the modem, which includes
RS422/EIA530 DCE, V.35 DCE, X.21 DCE and DTE and RS232, sync and async. Note that,
unlike many other products of this type, electrical interface types may be mixed within the
same redundancy group.
The CRS-200 incorporates the following key reliability features:
* The CRS-200 has twin, independent AC power supplies
* Normal traffic paths are maintained, error free, when AC power is removed
* A Traffic Modem Interface can be completely removed from the CRS-200, with its
cables still attached, and traffic will be not be interrupted
* Traffic Modem Interfaces (TMI) and the Redundant Modem Interface (RMI) can be
replaced without disturbing other traffic circuits
When operating with a single up/downconverter, the system comprises a maximum of 10
Traffic Modems, a Redundant Modem, and the CRS-200 Protection Switch. All IF inputs and
outputs are passively split and combined. The redundant modem is in remote control mode,
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CRS-200 COMTECH COMMUNICATIONS CORPORATION
and the traffic modems may be in local or remote mode. All of the modems are connected
to the CRS-200 Protection Switch via a single 25-pin cable (which connects, data, alarms,
and an RS232 link). The RS232 link permits the CRS-200 to determine and store a modem’s
configuration, and to send a chosen configuration to the Redundant Modem.
IF switching is distributed - each Modem has an internal RF relay, which is normally under
the control of the Modem’s internal software. However, there is a direct hardware connection
that over-rides the processor setting, and turns the carrier off. All the transmit outputs of the
modems are connected to a passive IF combiner, and the IF outputs from a Traffic or
Redundant Modem can be enabled or disabled via a hardware command from the CRS-200.
For the receive IF, all of the Traffic Modems, and the Redundant Modem are fed with
identical signals from a passive IF distribution system. In this way, the Redundant Modem can
demodulate any of the input carriers going to the Traffic Modems.
The data and clock signals, to and from a Traffic Modem, are routed through a Traffic
Modem Interface (TMI), via a set of relays. This is arranged so that the de-energised
(unpowered) state connects the data signals directly through to the Traffic Modem. If the
power supplies to the system are lost, or if a TMI carrying traffic is removed, no interruption
of the traffic will take place. It should also be noted that in normal circumstances, where the
Redundant Modem is not in service, no data is carried through the CRS-200 backplane - all
data is routed via the TMI.
A key feature of the CRS-200 architecture is its ability to let the Redundant Modem ‘bridge’
a Traffic Modem. A copy of the data and clock signals feeding a particular Modem can be
selectively routed to the Redundant Modem, and the RX IF can be tuned to receive any
selected carrier. This has the advantage that no external test equipment is needed to
determine the health of the Redundant Modem - live traffic is used at all times to verify
performance.
The CRS-200 is fully modular in construction. All replaceable modules insert into slots in the
rear. This includes the Controller, PSU’s, TMI’s and the RMI. Power consumption is below
25 watts for a fully populated Switch, and hence no fan cooling is required.
Connection to the Traffic Modems and the Redundant Modem is remarkably simple - a single
cable is required for each modem, which carries all data signals, alarm information, and
remote control interfaces. This simplifies rack cabling, and reduces the number of potential
failure points.
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4 PHYSICAL DESCRIPTION
The CRS-200 is constructed as a 4U high rack-mounting chassis, that 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.
4.1 FRONT PANEL - See Figure 1
On the front panel of the unit are the Vacuum Fluorescent Display (VFD), keypad, and
several LED indicators. The user enters data via the keypad, and messages are displayed on
the VFD. Behind the front panel there is also an audio alarm, that can be controlled to
respond to various faults.
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 3 LED indicators at the top of the front panel that reflect the condition of the switch
itself. The functions of these indicators are shown in Table 1 below.
TABLE 1 - SWITCH LED INDICATORS
LED Color Condition
Unit Status
Stored
Event
Remote
Red A Switch Fault exists (Example: PSU fault)
Green No Switch Faults
Off There are no Stored Events
Orange There are Stored Events, either for the switch itself or the
modems attached to it
Off The Switch is in Local Mode - remote monitoring is possible,
but no remote control
Orange The Switch is in Remote Mode – control changes are
disabled via the front panel keypad
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There are 5 LED indicators for each of the 10 TMIs that may be plugged into the rear of the
switch, and 4 of the 5 are repeated an eleventh time for the RMI. These are described in
Table 2 below.
TABLE 2 – MODEM LED INDICATORS
LED Color Condition
Unit Status
Red A Unit Fault exists
Orange
Green No Unit Faults, or Traffic Faults
Transmit
Traffic
Receive
Traffic
On line
Bridged
The last indicator is not repeated for the redundant modem, since it cannot bridge itself.
4.2 REAR PANEL - see Figure 2
External cables are attached to connectors on the rear panel of the CRS-200’s plug-in
modules. These comprise the IEC line input connectors, the Data connectors to each
modem, the User Data Interface connector for each traffic modem to the outside world,
the System Alarms connector, the Remote Control connector, and Auxiliary RS-485
connector.
Green No Tx Traffic Faults
Off
Green No Rx Traffic Faults
Off
Green The Unit is On Line, and carrying traffic
Off The Unit is Off Line (standby) - forced by the Switch
Orange Modem is currently being Bridged by Redundant Modem
Off Modem is not being Bridged
No Unit Faults, but a Traffic Fault exists OR the TMI is not
plugged in
A Tx Traffic fault exists OR the TMI is not plugged in
An Rx Traffic fault exists OR the TMI is not plugged in
The IEC line input connector for each Power Supply Module contains the ON/OFF switch
for that module. 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.
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The Data connectors on the TMI plug-ins are 25 pin ‘D’ type male leading to/from the
modems, and female leading to/from the outside world (User Data). These conform to the
EIA 530 pinout, which allows for connection of different electrical standards, including
RS422, V.35, and RS232. Please note that it is the responsibility of the user to provide the
appropriate cables to connect to these EIA 530 connectors. A shielded 25 pin ‘D’ type
provides a very solid solution to EMC problems, unlike the V.35 Winchester connector. The
male connector to/from the modem requires a simple pin-to-pin cable with connectors of
opposite sex so that the other end can plug into the modem’s Data connector. The female
connector can then be treated as an extension of the traffic modem’s Data connector. The
RMI has no User Data connector since it will only replace one of the traffic modems. The
pinout for both connectors is provided in the next section.
The System Alarms connector on the System Controller card is another 25 pin female D-sub.
This provides the user with access to Form-C relay contacts that indicate the fault status of
the switch and the summary faults for the three modem alarm types. If any of the attached
modems has one of the three faults active, the corresponding relay will energize, forcing the
normally open pin to connect to (and the normally closed pin to disconnect from) the
common pin. There are also relay contacts to indicate which, if any, of the traffic modems
is currently being backed up. Another pin provides a ground connection when the audio
alarm is sounded so that additional sounders may be added by the user. The pinout details
for this connector are provided in the next section.
The IF Switch Control connector is a 25 pin male D-sub that should be cabled directly to the
corresponding connector on the CRS-280 Transponder Switch, if used. This not only supplies
power to the CRS-250, but also indicates the currently selected traffic modem and whether
the system is in bridged or back-up mode. The CRS-280 must perform the same bridging and
backing up functions to the transmit and receive IF signals to match what the CRS-200 does
to the terrestrial data signals. The pinout of this connector is provided in the next section.
The Remote Control connector is a male 9 pin D-sub. Access is provided to remote control
ports of the switch, both RS232 and RS485. The pinout details for this connector are
provided in the next section.
The Auxiliary Serial connector is another 9 pin D-sub, this one female. It is currently unused,
but is reserved for use as an additional RS-485-only remote link that may be added on future
revisions of the switch.
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5 FUNCTIONAL DESCRIPTION
The CRS-200 is a 1-for-N redundancy controller, meaning that a single redundant modem
(referred to as an RM) can be employed as a backup in the event of a failure to any one of
up to 10 traffic modems (referred to as a TM). An overall system is shown in Figure 3. The
front panel includes system status LEDs that indicate the current fault status of all the modems
connected to the switch. In addition, there are LEDs for the modems’ online status and, for
the traffic modems, an indication of which modem is currently being “bridged” by the
redundant modem. This means that the redundant modem has been programmed to match
the configuration of that selected traffic modem, and is being fed with a copy of the traffic
signals that the TM sees.
In addition to the main chassis, there are 4 different types of plug-in units, all of which are
fastened at the rear of the chassis using hand-tightened captive screws. These are the
Redundant Modem Interface (CRS-210), of which one is required in the leftmost slot while
looking at the rear of the chassis; the Traffic Modem Interface (CRS-220), of which one is
needed for each traffic modem to be used and can occupy any of the other ten slots; the
System Controller (CRS-230), of which one is required; and the Power Supply Module (CRS-
240), for which 2 slots are provided so that the switch can operate with either/both installed.
The Redundant Modem Interface (RMI) card has a single 25-pin male D-sub connector that
is attached to the redundant modem’s primary data connector with a shielded cable. This
connection between the RMI and the redundant modem includes fault relay status from the
modem to the switch as well as an RS-232 remote control link, so that no other
interconnections are required. Transmit terrestrial signals normally sent to the bridged traffic
modem are also routed to the redundant modem through this connection. When the
redundant modem is put online, all terrestrial signals from the redundant modem replace
those of the traffic modem that was taken offline. An online LED is also present that matches
the corresponding Redundant Modem Online indicator on the switch’s front panel.
Each traffic modem is connected to the switch by its Traffic Modem Interface (TMI) card. The
same type of 25-pin cable used on the RMI should be used to connect the TMI to the traffic
modem’s primary data connector, again with fault status and RS-232 remote link included.
A second connector on the TMI (this one female) serves as the terrestrial data interface. The
TMI modules are designed so that they may be inserted or removed while the switch is
turned on, without causing interruptions to the data traffic. The TMIs also have a rear Online
LED, as well as a Bridged LED that also matches the front panel version. Any switch that is
ordered with fewer than 10 TMI cards will have blank plates installed in place of TMI cards
in the last unused slots.
The System Controller card is the heart of the switch, containing a 16-bit microcontroller,
flash-upgradable PROM and non-volatile memory. In addition to a 9-pin D-sub connector
(male) for remote communication between the switch and a PC in either RS-232 or RS-485
format, the System Controller also has a 25-pin connector (male) for interfacing the switch
to the Comtech IF transponder switch, a 25-pin connector (female) for switch and modem
alarm relay outputs and another 9-pin (female) connector that is reserved for a possible
auxiliary RS-485 remote link.
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A CRS-240 Power Supply Module is installed in each side of the chassis. If one module is
removed while power is on, the system continues to operate with no disturbance. This allows
servicing of a module without interruption. The controller monitors the +5V, +12V and –12V
supplies of each module separately, and any fault reported on either module can be masked
if the user chooses to operate without a backup in place. Module A is on the right and
Module B is on the left as viewed from the rear of the chassis.
The microcontroller in the CRS-200 continuously scans the system to gather information. This
information is then used to determine if action needs to be taken. Every second, three status
checks are performed. First, all 11 modem interface positions are checked in succession for
the presence of an interface card and, if present, all three modem alarm relay conditions are
checked. If a modem interface is present but no modem is connected with the 25-pin cable,
all three fault indicator LEDs on the front panel will show the faulted state. Unmasked faults
are logged.
Second, the switch checks itself for faults. These consist of either power supply faults or a
failure to communicate remotely with the redundant modem, and are also logged if
unmasked. The outputs of both power supplies are monitored for both overvoltage and
undervoltage conditions, but only one supply may have its faults masked at a time. A remote
communication fault with the redundant modem may not be masked, since the switch
requires this to operate. Both modem and switch alarms also cause an update to the switch’s
own relay outputs on the rear panel of the System Controller card.
Third, one of the 11 modems is checked for a configuration change on each one second
interval. So, over an 11 second period, any change made to a modem either remotely or via
the front panel will automatically cause an update to that modem’s configuration which is
stored in the switch’s memory. If the switch has been in operation with a modem or its TMI
is missing, so that it has never saved a configuration for that position, that position is not
allowed to become activated. The switch, however, continues to check the unoccupied
position at each pass, so that adding a modem later will result in a configuration being found
by the switch and the modem position may then be activated. If a modem is removed or fails
such that communication is lost, the last stored configuration remains in the switch’s
memory.
After each one second status check, the switch uses the current status information in
conjunction with its own configuration to decide to “backup” or “bridge”. When the
redundant modem “bridges” a particular traffic modem, the redundant modem is reconfigured to match the selected traffic modem using the stored configuration, and is fed
with a copy of the traffic modems signals. To “back-up” that traffic modem, a series of relay
changes on the selected TMI puts the redundant modem online in place of the traffic modem.
In both cases, the RM and the selected TM are in parallel with each other, meaning that
transmit terrestrial signals are sent to both modems simultaneously. By virtue of being set to
the same receive parameters (such as IF frequency and data rate) and being cabled together,
their demodulators will lock to the same signal. Figure 4 shows how the data paths change
when a traffic modem is taken offline in place of the redundant modem. When a
configuration change occurs to either the bridged TM or the RM itself, the switch will
automatically reconfigure the RM to match the TM it is bridging.
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6 CONNECTOR PINOUTS
6.1 DATA CONNECTOR - 25 PIN ‘D’ TYPE MALE AND FEMALE
Pin Generic Signal description Direction RS422/ V.35 RS232 Circuit
EIA 530 No
2 Transmit Data A DTE to Modem SD A SD A BA 103
14 Transmit Data B DTE to Modem SD B SD B - 103
24 Transmit Clock A DTE to Modem TT A SCTE A DA 113
11 Transmit Clock B DTE to Modem TT B SCTE B - 113
15 Internal Transmit Clock A Modem to DTE ST A SCT A DB 114
12 Internal Transmit Clock B Modem to DTE ST B SCT B - 114
3 Receive Data A Modem to DTE RD A RD A BB 104
16 Receive Data B Modem to DTE RD B RD B - 104
17 Receive Clock A Modem to DTE RT A SCR A DD 115
9 Receive Clock B Modem to DTE RT B SCR B - 115
8 Receiver Ready A Modem to DTE RR A RLSD * CF 109
10 Receiver Ready B Modem to DTE RR B - - 109
23 External Carrier Off DTE to Modem - - - -
(RS232 ‘1' or TTL ‘low’ )
7 Signal Ground - SG SG AB 102
1 Shield - Shield FG AA 101
NOTES:
* Receiver ready is an RS232-level control signal on a V.35 interface
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
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