Introduction; Description; Led Indicators; Transmission Methods - Siemens MJ-4 Series Installation Manual

1 Introduction

This manual describes the installation and connection procedures for the MJ-4A
TM
to collectively as MJ-4
combined in one single printed circuit board. The operation and functionality of the Fiber Optic and the RS-232-
/485 interfaces are quite similar, only one of the interfaces can be used at a time. The manual covers the procedures
for connecting the module to a system of networked MJ-4 Tap Changer Control Panels.

1.1 Description

The Siemens MJ-4 Communications Module is the communication interface used to connect the MJ-4 Control Panel
to a network of regulator controllers, control devices, and supervisory equipment. Figure 1-1 illustrates the MJ4
Communications Module.
The fiber optic interface enables connection of the tap changer control panel to the supervisory equipment via
multimode fiber optic cable. The RS-232/485 interface enables connection of the tap changer control panel to the
supervisory equipment via electrical wire.
The MJ-4 Communications Module is installed in MJ-4 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. An
adapter kit is available for mounting MJ-4 Communications Modules in MJ-X Control Panels.
POWER
Watchdog

1.2 LED Indicators

The MJ-4 Communications Module has five LED indicators.
•
Power indicates the MJ-4 Communications Module is powered on.
•
Watchdog when blinking steadily, indicates the MJ-4 Communications Module microprocessor and software
are functioning properly.
•
Communications indicates communications activity with this module. (The Communications Module turns on
this indicator when it receives a valid message with a valid address.)
•
Rxd indicates the communications module is receiving data.
•
Txd indicates the communications module is transmitting data.

2 Transmission Methods

There are two transmission mediums available for sending data to the RTU:
•
fiber optic
•
wire
) Communications Module which has the Fiber Optic and the RS-232/485 interfaces
RS - 232 / 485
Communications Module
IN
Communications

Figure 1-1 MJ-4 Communications Module.

MJ-4 Communications Module
TM
& MJ-4B
G R Data R
N T x
D N - + d
OUT
Rxd Txd
TM
(here after referred
T C R
x T T
d S S
1