5
X
RS-232,485 + 2
X
E
THERNET
/2 M
BIT
/
S
G.703 (G.704) M
ULTIPLEXER
O
PERATING
M
ANUAL
IOA81-1E
18
August 2004
In the examples shown on Fig. 20, the multiplexers TM-81.1 (A) and TM-81.1 (D) are
configured as terminal devices. If the multiplexer A will operate with the internal clock and
the multiplexer D with the clock reproduced from the G.703 interface, then transmission in
both directions is fully synchronous. A and D multiplexers may also operate independently
with their own internal clocks. However operation of both multiplexers, configured as termi-
nal devices, with reproduced clocks is not possible.
The clock source is selectable by using CONFIGURATION switches (see point 5.5 –
Se-
lection of operating mode)
.
TM
-81
(A
)
TM-81(B)
TM-81(C)
TM
-8
1(
D)
G
C
DR
Clock path in the A-D direction
Clock path in the D-A direction
Fig. 20.
Configuration of the clock for the chain of TM-81.1 multiplexers
4 Installation and Operation
4.1 Introduction
Prior to putting the multiplexer into normal service, it is necessary to install it and set-up
properly, in accordance with recommendations given below.
4.2 Operating
conditions
The TM-81.1 multiplexer can operate continuously in closed rooms in environmental
conditions presented in the „
Specifications”
chapter. The device should not be exposed to
direct sunlight. Ventilation slots in the multiplexer housing must not be clogged. It is not rec-
ommended to stand the device on heat-emitting objects, although it can be placed on other
identical device or installed in the rack in which other devices work. In this case an unre-
stricted flow of air should be ensured or, if necessary, forced ventilation system installed.
4.3 Installation
The TM-81.1 multiplexer can operate as a standalone device or be mounted in 19 or 21
inches rack. For installation in the rack, special mounting brackets included in delivery should
be screwed to side walls of the device.
