Integral Outstation Transmission Unit (Otu/Lmu); General Overview - Siemens TC12 Installation, Commissioning And Maintenance Handbook

6

INTEGRAL OUTSTATION TRANSMISSION UNIT (OTU/LMU)

6.1

GENERAL OVERVIEW

This section describes the Integral OTU/LMU. This is an additional PCB that can
be used in the TC12 System. It can be fitted in T400 or ST800 traffic controllers or
the ST700 pelican controller and used to communicate with a central office
Instation Transmission Unit. In this respect the description of the relationship
between OTUs and ITUs, given in the TC12 System Overview of section 1.6, is
applicable. However there are a number of differences between the Integral OTU
described in this section and the Freestanding OTU described in detail in Section
3. The main difference is that the Integral OTU can only be fitted in T400 and
ST800 Traffic Controllers and the ST700 Pelican Controller. The Freestanding
OTU on the other hand can be fitted to a variety of traffic controllers.
In more detail the differences between the Integral OTU and the Freestanding
OTU are as follows:
The Integral OTU does not contain the two input/output connectors (used on the
freestanding OTU to connect to the controller and/or detector cards), instead it
contains a connector which is attached to the Extended System Bus Cable. All
Information between the Controller and the Integral OTU is exchanged over this
extended system bus.
The Integral OTU does not contain a separate handset port but is configured using
a handset attached to the Controller.
The Integral OTU uses the UD facilities of the host controller. Handset commands
such as CUD and UDT require maintenance level access as they are ST400/800
commands.
The Integral OTU can provide an LMU/RLM facility on the T400 only, and a
connector allows current and voltage monitoring transformers to be attached for
this purpose.
There is a pair of test jacks on the board to allow connection to the instation test
set to monitor communications data and measure signal levels.
Note that except for physical board installation and LMU Voltage sensing the
Integral OTU is the same as the Freestanding OTU. For message protocol and
handset commands etc refer to earlier sections of the handbook. This Section
details the differences between the Freestanding OTU and the Integral OTU.
See 667/1/25190/000 and 667/DZ/25190/000 for options available and family tree
for this product. These are not included in this manual.
666/HE/43100/000
TC12 Installation, Commissioning & Maintenance Handbook
Page 167 Issue 10