Siemens MJ-X Series User manual

MJ-X™ Communications Module
Fiber Optic and RS-232/485
Installation Manual
POWER
Watchdog
Communications
Rxd
Txd
GND
RTN
-
+
Rxd
Txd
CTS
RTS
Data
RS-232/485 Fiber Optic
Communications Module Communications Module
RS-232/485 Fiber Optic
Version 2 Version 1
Manual No. 21-115527-013-01

MJ-X Communications Module
DANGER
This equipment contains hazardous voltages.
Will cause death or serious Injury.
To prevent:
De-energize and ground the equipment before
maintenance.
Only qualified personnel should work on this
equipment after becoming thoroughly familiar
with all warnings, safety notices, instructions
and maintenance procedures contained
herein. The successful and safe operation of
this equipment Is dependent upon proper
handling, installation, operation and
maintenance.
The information contained herein is general in nature and not intended for specific application purposes. It does not relieve the user
of responsibility to use sound practices in application, installation, operation, and maintenance of the equipment purchased.
Siemens reserves the right to make changes in the specifications shown herein or to make improvements at any time without notice
or obligations. Should a conflict arise between the general information contained in this publication and the contents of drawings or
supplementary material or both, the letter shall take precedence.
NOTE
Authorized and qualified Personnel
For the purpose of this manual a qualified person is one who is familiar with the installation, construction or operation of the
equipment and the hazards involved. In addition, he has the following qualifications:
(a) Is trained and authorized to de-energize, clear, ground, and tag circuits and equipment in accordance with established
safety practices.
(b) Is trained in the proper care and use of protective equipment such as rubber gloves, hard hat, safety glasses or face
shields, flash clothing, etc., in accordance with established safety practices.
(c) Is trained in rendering first aid.
SUMMARY
These instructions do not purport to cover all details or variations in equipment, nor to provide for every possible contingency to be
met in connection with installation, operation, or maintenance. Should further information be desired or should particular problems
arise which are not covered sufficiently for the purchaser's purposes, the matter should be referred to the local sales office, listed on
the back of this instruction guide.
The contents of this instruction manual should not become part of or modify any prior or existing agreement, commitment or
relationship. The sales contract contains the entire obligation of Siemens Power Transmission & Distribution LLC, The warranty
contained in the contract between the parties is the sole warranty of Siemens Power Transmission & Distribution LLC. Any
statements contained herein do not create new warranties or modify the existing warranty.
DANGER Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
WARNING Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
CAUTION Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.

MJ-X Communications Module
Table of Contents
1 INTRODUCTION ...............................................................................................................................................1
1.1 DESCRIPTION ..................................................................................................................................................1
1.2 FRONT PANEL LED INDICATORS....................................................................................................................2
2 TRANSMISSION METHODS...........................................................................................................................2
2.1 FIBER OPTIC TRANSMISSION ..........................................................................................................................3
2.2 WIRE TRANSMISSION......................................................................................................................................3
2.2.1 RS-232...................................................................................................................................................3
2.2.2 RS-485...................................................................................................................................................4
2.3 COMMUNICATION PROTOCOLS .......................................................................................................................5
3 INSTALLATION (VERSION 2)........................................................................................................................5
3.1 JUMPER SETTINGS ..........................................................................................................................................6
3.1.1 Fiber Optic Version ...............................................................................................................................6
3.1.2 RS-232/485 Version ..............................................................................................................................7
3.2 COMMUNICATIONS MODULE INSTALLATION ..................................................................................................8
4 INSTALLATION (VERSION 1)......................................................................................................................10
4.1 EXPANSION RACK INSTALLATION ................................................................................................................11
4.2 JUMPER SETTINGS ........................................................................................................................................13
4.2.1 Fiber Optic Board ................................................................................................................................13
4.2.2 RS-232/485 Board ...............................................................................................................................14
4.2.3 Microprocessor Board .........................................................................................................................15
4.3 MODULE INSTALLATION...............................................................................................................................16
5 TESTING ...........................................................................................................................................................16
5.1 INITIAL DIAGNOSTIC CHECKOUT ..................................................................................................................17
5.2 LOOPBACK DIAGNOSTIC TEST ......................................................................................................................17
6 CABLING ..........................................................................................................................................................18
6.1 FIBER OPTIC CABLE TYPE ............................................................................................................................18
6.1.1 Fiber Optic Cable Lengths...................................................................................................................18
6.1.2 Fiber Optic Connector .........................................................................................................................18
6.1.3 Fiber Optic Connections ......................................................................................................................19
6.2 RS-485 TWISTED-PAIR CABLE .....................................................................................................................19
6.2.1 RS-485 Cable Type..............................................................................................................................19
6.2.2 RS-485 Cable Grounding ....................................................................................................................19
6.2.3 RS-485 Connector ...............................................................................................................................20
6.3 RS-232 CONNECTIONS .................................................................................................................................20
6.3.1 RS-232 Multi-drop Wiring ..................................................................................................................21
6.4 RS-232/485 CONNECTIONS ..........................................................................................................................22
6.5 COMMUNICATIONS MODULE CONFIGURATION.............................................................................................22
6.5.1 Communications Menu Item Descriptions ..........................................................................................24
6.6 TROUBLESHOOTING COMMUNICATIONS PROBLEMS .....................................................................................24
6.6.1 Using LEDs to Help Diagnose Communications Problems ................................................................25
6.6.2 Using MJXplorer to Troubleshoot Communications Problems...........................................................25
7 SPECIFICATIONS ...........................................................................................................................................26
7.1 PHYSICAL DIMENSIONS ................................................................................................................................26
7.2 FIBER OPTIC LINK MODULE SPECIFICATIONS...............................................................................................27
7.3 RS-232/RS-485 MODULE SPECIFICATIONS ..................................................................................................27

MJ-X Communications Module
Figures
FIGURE 1-1 MJ-X COMMUNICATIONS MODULES, VERSION 2........................................................................................1
FIGURE 1-2 MJ-X COMMUNICATIONS MODULES, VERSION 1........................................................................................2
FIGURE 2-1 FIBER OPTIC NETWORK...............................................................................................................................3
FIGURE 2-2 RS-232 CONNECTION..................................................................................................................................3
FIGURE 2-3 MODEM CONNECTION .................................................................................................................................4
FIGURE 2-4 RS-485 CONFIGURATIONS ..........................................................................................................................5
FIGURE 3-1 FIBER OPTIC VERSION JUMPER LOCATIONS ................................................................................................6
FIGURE 3-2 RS-232/485 VERSION JUMPER LOCATIONS .................................................................................................6
FIGURE 3-3 MJ-X CONTROL PANEL REAR COVER .........................................................................................................8
FIGURE 3-4 COMMUNICATIONS MODULE INSTALLATION ...............................................................................................9
FIGURE 3-5 MEMBRANE SWITCH CABLE ROUTING ........................................................................................................9
FIGURE 3-6 MJ-X COMMUNICATIONS MODULE CABLE ROUTING................................................................................10
FIGURE 4-1 MJ-X CONTROL PANEL REAR COVER .......................................................................................................11
FIGURE 4-2 EXPANSION RACK INSTALLATION .............................................................................................................12
FIGURE 4-3 MJ-X MEMBRANE SWITCH CABLE ROUTING ............................................................................................12
FIGURE 4-4 FIBER OPTIC BOARD JUMPER LOCATIONS .................................................................................................13
FIGURE 4-5 RS-232/485 BOARD JUMPER LOCATIONS..................................................................................................15
FIGURE 4-6 MICROPROCESSOR BOARD JUMPER SETTINGS ...........................................................................................15
FIGURE 4-7 VERSION 1 MODULE INSTALLATION..........................................................................................................16
FIGURE 6-1 FIBER OPTIC CONNECTIONS.......................................................................................................................19
FIGURE 6-2 RS-485 CONNECTION................................................................................................................................20
FIGURE 6-3 SCREW TERMINAL BLOCK CONNECTOR ....................................................................................................20
FIGURE 6-4 RS-232 MULTI-DROP CONFIGURATION .....................................................................................................21
FIGURE 6-5 RS-232 CONNECTOR PINOUT ....................................................................................................................22
FIGURE 6-6 SCREW TERMINAL CONNECTION ...............................................................................................................22
FIGURE 6-7 MJXPLORER TROUBLESHOOTING CONNECTIONS ......................................................................................26
Tables
TABLE 3-1 FIBER OPTIC VERSION JUMPER SETTINGS.....................................................................................................7
TABLE 3-2 RS-232/485 BOARD JUMPER SETTINGS........................................................................................................7
TABLE 4-1 FIBER OPTIC BOARD JUMPER SETTINGS .....................................................................................................14
TABLE 4-2 RS-232/485 BOARD JUMPER SETTINGS......................................................................................................14
TABLE 4-3 MICROPROCESSOR BOARD JUMPER SETTINGS ............................................................................................15
TABLE 6-1 RS-485 CABLE SPECIFICATIONS.................................................................................................................19
TABLE 6-2 RS-232 INTELLIGENT ELECTRONIC DEVICE WIRING..................................................................................21
TABLE 6-3 MODEM WIRING .........................................................................................................................................21
TABLE 6-4 COMMUNICATIONS MENU ITEMS ................................................................................................................23
ACCESS is a trademark of Siemens Energy & Automation, Inc. MJ-X and MJXplorer are trademarks of Siemens
Power Transmission & Distribution LLC. Siemens is a registered trademark of Siemens AG.
1994 - 1999 Siemens Power Transmission & Distribution LLC

MJ-X Communications Module
1
1 Introduction
This manual describes the installation and connection procedures for the MJ-XCommunications Modules.
Information is provided for both Version 1 and Version 2 Communications Modules. The operation and
functionality of both versions are quite similar; the mechanical configurations and installation procedures are
different. The manual also covers the procedures for connecting the module to a system of networked MJ-X Tap
Changer Control Panels.
1.1 Description
The Siemens MJ-X Communications Module is the communication interface used to connect the MJ-X Control
Panel to a network of regulator controllers, control devices, and supervisory equipment. The module is available
with either a fiber optic or RS-232/485 interface. Figure 1-1 illustrates the Version 2 Communications Modules.
Figure 1-2 illustrates the Version 1 Communications Modules (to be discontinued mid-1999).
The fiber optic module enables connection of the tap changer control panel to the supervisory equipment via multi-
mode fiber optic cable. The RS-232/485 module enables connection of the tap changer control panel to the
supervisory equipment via electrical wire.
The communications modules are installed in MJ-X Tap Changer Control Panels. This allows you to easily network
the control panels and other field devices to a remote terminal unit (RTU) or other supervisory device.
POWER
Watchdog
Communications
Rxd
Txd
GND
RTN
-
+
Rxd
Txd
CTS
RTS
Data
RS-232/485 Fiber Optic
Communications Module Communications Module
R
S
-232
/
485 Unit Fiber
O
ptic Unit
Figure 1-1 MJ-X Communications Modules, Version 2 (Permanent Mount)

MJ-X Communications Module
2
Fiber Optic Unit
MJ-
X
Fiber Optic
Communications
Module
Rxd
Txd
Po
w
er
WDog
Comm
In
Out
RS-232/485 Unit
MJ-
X
RS-232/485
Co
m
m
unications
Module
Rxd
Txd
Po
w
er
WDog
Comm
GND
RTN
-
+
Rxd
Txd
CTS
R
TS
Data
Figure 1-2 MJ-X Communications Modules, Version 1 (Expansion Rack Plug-in)
1.2 Front Panel LED Indicators
The MJ-X Communications Module has five LED indicators.
• Power indicates the MJ-X Communications Module is powered on.
• Watchdog (“Wdog”) blinks steadily to indicate the MJ-X Communications Module microprocessor and
software are functioning properly.
• Communications (“Comm”) indicates communications activity with this module.
• Receive Data (Rxd) indicates the communications module is receiving data.
• Transmit Data (Txd) indicates the communications module is transmitting data.
2 Transmission Methods
The MJ-X Communications Modules comes in two varieties to support 1) fiber optic and 2) wire (RS-232/485)
transmission mediums.

MJ-X Communications Module
3
2.1 Fiber Optic Transmission
The primary benefits of fiber optic communications are its immunity to induced electrical interference and relatively
low signal loss. Electrical noise cannot be induced into the cable to generate transient spikes that disrupt data
communications.
The MJ-X Fiber Optic Communications Module uses multi-mode fiber optic cable. The electrical signals are
converted to optical signals by the communication unit. The optical signals are then transmitted via the fiber optic
cable to the RTU. Communications modules in the path between the transmitting communications module and the
RTU act as repeaters and simply regenerate the signals and forward them to the next device, Figure 2-1.
RTU Fiber Optic Cables
MJ-X MJ-X MJ-X
Out
Out Out Out
In
In In In
Figure 2-1 Fiber Optic Network
2.2 Wire Transmission
The advantage of wire transmission is simple installation. The MJ-X supports two popular wire interfaces: RS-232
and RS-485. The screw terminal block connector supplied with the module can be wired for either interface.
Connection to the supervisory device is typically accomplished using either a DE-9 or DB-25 connector for RS-232,
while the connector used for RS-485 will vary with the application.
2.2.1 RS-232
Direct RS-232 connections are limited to a maximum distance of 50 feet, Figure 2-2. The MJ-X RS-232/485
Communications Module supports RS-232 multi-drop configurations.
The distance between devices may be extended with modems, Figure 2-3. Modem connections are dial-up, short-
haul, or radio-based. Dial-up modems are typically deployed when there is easy access to the telephone connections,
while short-haul modems are useful within a facility where there is access to the wiring. Consider using a radio
modem when laying cable for a telephone line modem is impractical.
RTU MJ-X MJ-X
50 Feet
RS-232 Cable
50 ft Max.
Figure 2-2 RS-232 Connection

MJ-X Communications Module
4
RTU
M
o
d
e
mM
o
d
e
m
MJ-X
RS-232 Cable
50 ft Max.
RS-232 Cable
50 ft Max.
Figure 2-3 Modem Connections
2.2.2 RS-485
The maximum distance for RS-485 is 4000 feet, either from device to device or for an entire loop. The
recommended cable for RS-485 is shielded, twisted-pair, 22 AWG. This type of cable consists of jacketed wire that
is twisted together and wrapped in a shield to prevent electromagnetic interference from affecting the data signal. A
maximum of 32 devices can be connected to an RS-485 network. Typical network configurations are loop, star, and
open-ended. These are shown in Figure 2-4. The recommended network configuration is a loop. This will ensure
that all devices remain connected to the master unit in the event of a line break. If the loop configuration does not
allow you to place the equipment in the desired location, connect the network open ended.
If either the star or open-ended configurations are used, termination resistors must be installed at the end devices.
For more information on installing RS-485 networks, refer to Siemens publication SG-6028, Installing the
ACCESS™ System. The following characteristics determine the maximum length and data rate of an RS-485
network.
Impedance: The maximum transfer of energy occurs when the cable’s terminating impedance matches the
characteristic impedance of the cable. If the cable’s characteristic impedance is 120 ohms, use a 120 ohm
terminating resistor.
Capacitance: Wire capacitance affects the rise and fall times of a transmitted signal and, as a result, limits the
signaling (baud) rate of the data. The higher the capacitance, the lower the maximum baud rate. Additionally,
higher capacitance requires higher output current to drive the line. Since capacitance is proportional to wire
length, it can limit the maximum cable length for a given baud rate.
Cable Size: Cable size, along with capacitance and DC resistance, determines whether the cable is suitable for
the application. A 22-gauge cable will provide a proper balance of capacitance and resistance.
DC Resistance: DC resistance determines the maximum length of wire allowed for an application. Determine
the maximum length from the resistance of each twisted pair along with the device termination resistance. The
use of surge protectors with series resistance also contributes to loop resistance.

MJ-X Communications Module
5
RTU
RTU
RTU
MJ-X
MJ-X
MJ-X
MJ-X
MJ-X
MJ-X
MJ-X
MJ-X
MJ-X
Twisted-pair
Cabling
4000 ft max. total
Twisted-pair
Cabling
4000 ft max. total
Twisted-pair
Cabling
4000 ft max. total
Figure 2-4a RS-485 Configuration - Loop Network
Figure 2-4b RS-485 Configuration - Star Network
Figure 2-4c RS-485 Configuration - Open-Ended Network
2.3 Communication Protocols
The MJ-X Control Panel can be used in a network of intelligent power control devices communicating with a
supervisory device or remote terminal unit (RTU). Each device on the network has a specific communications
address assigned to allow messages to be directed to and from the device. Messages are transmitted from the RTU
to all devices and only the device with the specified address will respond. The MJ-X Communications Module
supports the following protocols.
• Distributed Network Protocol (DNP 3.0) (Based on the IEC 870-5 Standard)
• The “Data 2200” Protocol (with or without address byte)
• MJ-3A Format “A”, “B1”, and “B2”
• The 2179 Protocol ( Based on the PG&E Protocol)
• Other (contact the factory for the latest list of supported protocols)
3 Installation (Version 2)
The MJ-X Communications Modules install in the back of the MJ-X Control Panel. Before installing the
communications module, set the jumpers on the communications module printed circuit board for proper operation.
Install the communications module in the MJ-X, connect the cables, and test the unit. Once these tasks have been

MJ-X Communications Module
6
performed the system is ready for operation. The following sections describe setting the jumpers, installing, and
testing the communications module.
3.1 Jumper Settings
Prior to installing the communication module into the MJ-X Control Panel, ensure that the jumpers are properly
installed on the printed circuit board. Jumper selections for the Fiber Optic version and RS232/485 version are
described in separate sections below.
3.1.1 Fiber Optic Version
The jumper locations on the fiber optic version are shown in Figure 3-1. The view of the module is from the
component side. The fiber optic receiver (RX) and transmitter (TX) are shown for reference. The jumper settings
are listed in Table 3-1.
Set Auto Repeat to no repeat when only one unit is installed in the network.
J11
J10
J12
12
J14
123
1
2
J11
123
J10
J12
J14
Figure 3-1 Fiber Optic Version Figure 3-2 RS-232/485 Version
Jumper Locations Jumper Locations

MJ-X Communications Module
7
Table 3-1 Fiber Optic Version Jumper Settings
Jumper Name Position Function Selected State Description
1-2 Auto Repeat Auto repeat for mark 0 or mark 1
2-3 No Repeat Force 0
J14 Auto Repeat
Out No Repeat Force 1 (no jumper installed at 1-2 or 2-3)
Out Normal Set Low Power Transmitter Output
J12 Range
In Long Set High Power Transmitter Output (See Note 2)
Note 1: Default pin settings are shown in bold text.
Note 2: If 50/125 µm cable is used, J12 must be jumpered (In). See section 5.1 for details.
3.1.2 RS-232/485 Version
Figure 3-2 shows the jumper locations on the RS-232/485 version, viewed from the component side. Jumpers and
their default settings are listed in Table 3-2.
In an RS-485 application, connect Signal Return (RTN) between the communication devices when there is a ground
potential rise between the connected devices. When the device RTN pins are connected, jumper J11 should be
disconnected (unless required by safety codes) to prevent ground loop currents.
Table 3-2 RS-232/485 Board Jumper Settings
Jumper Name Position Function Selected State Description
1-2 Receive Enable RS-485 receiver is always enabledJ10 RS-485
RCV EN 2-3 Auto Enable RS-485 receiver is automatically enabled by MJ-X
Communication Module microprocessor control.
Out Not grounded Signal Return not connected to frame groundJ11 Safety
Ground Strap In Grounded Signal Return connected to frame ground
Note: Default pin settings are shown in bold text.

MJ-X Communications Module
8
3.2 Communications Module Installation
Follow these steps to install the Version 2 communications module in the MJ-X Control Panel.
1. If the control panel is installed on a regulating device, first turn off the MJ-X power, then disconnect the
polarized disconnect switch (PDS) terminal block and remove the control panel from the housing.
2. Loosen the PDS cable strain relief on the rear cover and rotate the strain relief plate to the open position,
Figure 3-3.
Accessory Cover Plate
PDS Strain
R
e
li
e
fPl
a
t
e
Figure 3-3 MJ-X Control Panel Rear Cover
3. Remove the six screws on the side of the rear cover that hold it to the control panel.
4. Feed the PDS cable harness through the strain relief cutout while removing the rear cover.
5. Remove the accessory cover plate from the rear cover. Discard the accessory cover plate and mounting
hardware. If an Expansion Rack is installed in the accessory area, remove the rack. (This will not be used.)
6. Mount the communications module printed circuit board to the MJ-X base with six 6-32 x 7/16” standoffs,
Figure 3-4. Ensure that the membrane switch cable is folded over itself and under the communications module
printed circuit board as shown in Figure 3-5. [Two sets of stand-offs are included, one set with .25” threaded
length, and one set with .375” threaded length. To determine which stand-offs to use, examine the mounting
posts in the front panel. If they are threaded all the way to the top, use the .25” threaded-length set. Otherwise,
use the .375” threaded-length set. Use all six of the type that fits best.]

MJ-X Communications Module
9
6-32 x 3/8" Screw (6)
6-32 x 7/16" Male/Female
Standoff (6)
PCB
Cover Pan
MJ-X Base
Figure 3-4 Communications Module Installation
MJ-X Control Panel
Processor Board
Communications
Module
Membrane Switch Cable
Figure 3-5 Membrane Switch Cable Routing
7. Mount the communications module cover plate with six 6-32 x 3/8” screws as shown in Figure 3-4.
8. Plug the ribbon connector into J105 on the MJ-X Processor Board as shown in Figure 3-6.

MJ-X Communications Module
10
9. If you are installing the RS-232/485 version of the communications module, plug the power connector into
J411 on the MJ-X Power Board as shown in Figure 3-6.
Processor Board
Power Board
Connector J411
Connector J105
Txd
Rxd
GND
RTN
Data
Rxd
Txd
CTS
RTS
POWER
Wdog
Comm
Membrane Switch Cable
Figure 3-6 MJ-X Communications Module Cable Routing
10. Feed the PDS cable through the PDS strain relief opening in the rear cover.
11. Reinstall the rear cover of the control panel, attaching it using the six screws.
12. Rotate the PDS strain-relief plate to the closed position and tighten the screws for the strain relief plate.
13. Follow the procedure in section 5 (Testing) to test the communications module.
4 Installation (Version 1)
The “Version 1” MJ-X Communications Modules install in the expansion rack accessible at the back of the MJ-X
Control Panel. Once the expansion rack is installed, set the jumpers in the communications module for proper
operation. Install the communications module in the expansion rack, connect the cables, and test the unit. Once
these tasks have been performed the system is ready for operation. The following sections describe the installation
of the expansion rack and communications module in detail.

MJ-X Communications Module
11
4.1 Expansion Rack Installation
The expansion rack attaches to the MJ-X Control Panel. A power cable is supplied with the rack for connection to
the control panel. Install the expansion rack using the following steps.
1. If the control panel is installed on a regulating device, first turn off the MJ-X power, then disconnect the
polarized disconnect switch (PDS) terminal block and remove the control panel from the housing.
2. Loosen the PDS cable strain relief on the rear cover and rotate the strain relief plate to the open position, Figure
4-1.
Expansion Cover Plate
PDS Strain
Relief Plate
Rear Cover
Figure 4-1 MJ-X Control Panel Rear Cover
3. Remove the six screws on the side of the rear cover that hold it to the control panel.
4. Feed the PDS cable harness through the strain relief cutout while removing the rear cover.
5. Remove the expansion cover plate from the rear cover. Discard the cover plate and mounting hardware.
6. Plug one end of the power cable supplied with the rack into connector J208 on the expansion rack and plug the
other end into connector J411 on the power board of the control panel, Figure 4-2.

MJ-X Communications Module
12
Power Cable
MJ-X Control Panel
Ex
p
ansion Rack
Connector
J208
Connector
J411
Connector
J411
Rear View With
Rear Cover Removed
J105 Ex
p
ansion
Rack Connector
Membrane Switch
Cable
Side View
P
r
ocesso
r
Boa
r
d
Powe
r
Boa
r
d
Figure 4-2 Expansion Rack Installation
7. Position the expansion rack on the control panel and loosely install the six flat head screws. Ensure that the
membrane switch cable is folded over itself and under the expansion rack as shown in Figure 4-3.
MJ-X Control Panel
Expansion Rack
Membrane Switch
Cable
To p V i e w
Figure 4-3 MJ-X Membrane Switch Cable Routing
8. Plug the expansion rack cable into connector J105 on the control panel processor board as shown in Figure 4-2.
9. Tighten the six screws holding the expansion rack to the control panel.
10. Feed the PDS cable through the PDS strain relief opening in the rear cover.
11. Reinstall the rear cover of the control panel, attaching it using the six screws.
12. Rotate the PDS strain-relief plate to the closed position and tighten the screws for the strain relief plate.
13. You are now ready to install the communications module. Use the cover plates supplied with the expansion
rack to cover the unused slots.

MJ-X Communications Module
13
4.2 Jumper Settings
Prior to installing the communication module into the MJ-X Control Panel, ensure that the jumpers are properly
installed for all boards. Typically, only the jumpers on the transceiver board will have to be set.
4.2.1 Fiber Optic Board
Configure the fiber optic transceiver board jumpers to enable proper communications between devices. The jumper
locations on the fiber optic board are shown in Figure 4-4. The view of the module is from the component side. The
fiber optic receiver (RX) and transmitter (TX) are shown for reference. Remove the two screws on the left side of
the module case to access the circuit board. There are seven jumpers to configure. The jumper settings are listed in
Table 4-1. Remove the two screws on the left side of the module case to access the circuit board.
Ensure end-to-end compatibility by setting all TX and RX jumpers to mark 0 or mark 1 (see Table 3-1). If one is set
to mark 0 while the other is at mark 1, the fiber optic unit will act as an inverting repeater and will not transmit
correctly. If this occurs, check the jumpers and retry transmission.
Set Auto Repeat to no repeat when only one unit is installed in the network.
The TX/RX interface boards can be set to allow the LED to illuminate or remain off during an idle state. The RX
LED and TX LED are normally set the same. For example, if idle is set off, the LED will not light when the
transmitter is not transmitting, but will light when the transmitter goes active.
Rx
Tx
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
J608
Tx Shield
J607
Long Range
J609
Tx LED
J605
Tx State
J604
Rx LED
J603
Rx State
J606
Auto Repeat
Figure 4-4 Fiber Optic Board Jumper Locations

MJ-X Communications Module
14
Table 4-1 Fiber Optic Board Jumper Settings
Jumper Name Position Function Selected State Description
J603 RX State
1-2 Mark 0 Idle line logical 0 (no optical energy in link for mark)
2-3 Mark 1 Idle line logical 1 (optical energy in link for mark)
J604 RX LED
1-2 Mark 0 Idle line logical 0 RX LED Off
2-3 Mark 1 Idle line logical 1 RX LED Off
J605 TX State
2-3 Mark 0 Idle line logical 0 (no optical energy in link for mark)
1-2 Mark 1 Idle line logical 1 (optical energy in link for mark)
J606 Auto
Repeat
1-2 Auto Repeat Auto repeat for mark 0 or mark 1
2-3 No Repeat Force 0
Out No Repeat Force 1 (no jumper installed at 1-2 or 2-3)
J607 Range Out Normal Set Low Power Transmitter Output
In Long Set High Power Transmitter Output (See Note 2)
J608 TX Shield
In Ground Ties spare transmitter pins to GND
Out Float Floats spare transmitter pins
J609 TX LED
1-2 Mark 0 Idle line logical 0 TX LED Off
2-3 Mark 1 Idle line logical 1 RX LED Off
Note 1: In Table 4-1, default pin settings are shown in bold text.
Note 2: If 50/125 µm cable is used, J607 must be jumpered (In). See section 4.1 for details.
4.2.2 RS-232/485 Board
The RS-232/485 transceiver board must be configured to enable proper communications between devices. There are
two jumpers to be configured. The jumpers and their default settings are listed in Table 4-2. Figure 4-5 shows the
jumper locations on the RS-232/485 board viewed from the component side. Remove the two screws on the left side
of the module case to access the circuit board.
In an RS-485 application, connect Signal Return (RTN) between the communication devices when there is a ground
potential rise between the connected devices. When the device RTN pins are connected, jumper J565 should be
disconnected (unless required by safety codes) to prevent ground loop currents.
Table 4-2 RS-232/485 Board Jumper Settings
Jumper Name Position Description
J564 RS-485 RCV EN 2-3 RS-485 receiver is automatically enabled by MJ-X
Communications Module microprocessor control.
1-2 RS-485 receiver is always enabled.
J565 SAFETY GROUND
STRAP
OUT Signal Return not connected to frame ground
IN Signal Return connected to frame ground
Note: In Table 4-2, default pin settings are shown in bold text.

MJ-X Communications Module
15
Figure 4-5 RS-232/485 Board Jumper Locations
4.2.3 Microprocessor Board
The MJ-X Communications Module microprocessor board has three configurable jumpers. These jumpers are
factory set and should not be adjusted. Figure 4-6 shows the location of the jumpers. They should be factory set to
the positions listed in Table 4-3. To gain access to the circuit board, remove the two screws on the left side of the
module case.
Table 4-3 Microprocessor Board Jumper Settings
Jumper Position
J505 1-2
J506 2-3
J507 1-2
J505
J507
J506
123
123
135
Figure 4-6 Microprocessor Board Jumper Settings

MJ-X Communications Module
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4.3 Module Installation
The Version 1 communications module can be installed in any of the three slots in the expansion rack. Install the
module using the following steps.
1. Turn off power to the MJ-X Control Panel.
2. Remove the expansion module cover plate, if installed.
3. Align the communications module card edges that extend from the module case with the guide slots on the
expansion rack, as shown in Figure 4-7.
4. Firmly press the module into the rack until the module flanges are touching the rack.
5. Tighten the slotted screws on the module flanges to secure it in the rack.
6. Follow the Test procedure described in section 5 to test the communications module.
SIEMENS
Figure 4-7 Version 1 Module Installation
5 Testing
Once the MJ-X Communications Module is installed, test the module as follows to ensure proper operation and
performance.
1. Visually inspect the MJ-X Communications Module for proper mechanical assembly and cable connections.
2. Apply power to the MJ-X Control Panel and observe the LEDs on the communications module. The Power
LED should light immediately and stay lit. After 10 to 15 seconds, the Watchdog LED should start flashing
without a long pause between flashes, that is, about twice per second.
If this does not occur, check for the following:
 The MJ-X Control Panel is receiving power. Check that the front panel display is active.
 The communications module is installed properly. Connections between the MJ-X and the rack are correct.
Disassemble, inspect, and reassemble the unit as required.
 The MJ-X Control Panel Main Processor firmware is Version 2.41 or higher. Select the “Version” menu
item from the <CONFIGURE> menu of the MJ-X Control Panel.
3. After verifying that the communications module is receiving power, perform the “Initial Diagnostics Checkout”
(section 5.1.)