Overview Of The Tc12 Instation Test Set Settings/Selections And Connections; Introduction; Connection To Unit Under Test - Siemens TC12 Installation, Commissioning And Maintenance Handbook

4.3 OVERVIEW OF THE TC12 INSTATION TEST SET SETTINGS/SELECTIONS
AND CONNECTIONS

4.3.1 Introduction

The TC12 Instation test set (part number 667/1/22702/000) is used to monitor and
test the operation of the TC12 system. It can be used at all the TC12 baud rates
and at any signal level between 0dBm and -63dBm. There is a pair of headphones
that may be connected to the ITS to allow the user to listen to both control and
reply messages.
There are three modes of operation for the ITS; Monitor mode, Instation mode,
Outstation mode. Whichever mode the ITS is operating in, the physical connection
to the unit under test does not change.
The Test Set can also be used as a handset for configuring OTUs and as a
monitor for the Instation PC (for use during installation of the PC).

4.3.2 Connection to Unit Under Test

4.3.2.1 Control and Reply Test Jacks
The test set interfaces to the control and reply sockets on either a Modem PCB or
OTU PCB. A cable is provided with a 15-way D-type at one end and two jack plugs
at the other end. The D-type connects to the 'LINE INTERFACE' connector on the
test set front panel. The jack plugs connect to the line jack sockets of the PCB
under test. The control jack plug is marked with a white band. The reply jack plug
is unmarked. The control sockets on the Modem and OTU PCBs have a white bar
silk screened next to them to distinguish them from the reply socket.
4.3.2.2 Connection to the Modem PCB in the Instation
(1) System with Modem PCBs connected direct to MDF
There are four modems on one Modem PCB. For each modem there is a control
and reply jack socket. Modem 1 is connected to the top two sockets on the modem
PCB, modem 2 to the next pair of sockets, etc. For each pair of sockets the top
socket is the reply signal, and the bottom socket (with a white bar next to it) is the
control signal.
(2) Radial System with Modem PCBs and Transformer PCBs
Connection is made to the relevant modem PCB as described above. However
each of the four modems on the modem PCB communicates with up to eight
OTUs via the associated transformer PCB. Hence the signal at a control jack on
the Modem PCB will be sent to up to eight OTUs simultaneously. The signal at a
reply socket contains the reply from up to eight OTUs.
666/HE/43100/000
TC12 Installation, Commissioning & Maintenance Handbook
Page 141 Issue 10