Interface - GE B90 Instruction Manual

3.3 DIRECT INPUT/OUTPUT COMMUNICATIONS
a) DESCRIPTION
The following figure shows the 64K ITU G.703 co-directional interface configuration.
The G.703 module is fixed at 64 kbps. The
setting is not applicable to this module.
NOTE
AWG 24 twisted shielded pair is recommended for external connections, with the shield grounded only at one end. Con-
necting the shield to pin X1a or X6a grounds the shield since these pins are internally connected to ground. Thus, if pin X1a
or X6a is used, do not ground at the other end. This interface module is protected by surge suppression devices.
3
The following figure shows the typical pin interconnection between two G.703 interfaces. For the actual physical arrange-
ment of these pins, see the Rear terminal assignments section earlier in this chapter. All pin interconnections are to be
maintained for a connection to a multiplexer.
Figure 3–32: TYPICAL PIN INTERCONNECTION BETWEEN TWO G.703 INTERFACES
Pin nomenclature may differ from one manufacturer to another. Therefore, it is not uncommon to see pin-
outs numbered TxA, TxB, RxA and RxB. In such cases, it can be assumed that "A" is equivalent to "+" and
"B" is equivalent to "–".
NOTE
b) G.703 SELECTION SWITCH PROCEDURES
1. Remove the G.703 module (7R or 7S). The ejector/inserter clips located at the top and at the bottom of each module,
must be pulled simultaneously in order to release the module for removal. Before performing this action, control
power must be removed from the relay. The original location of the module should be recorded to help ensure that
the same or replacement module is inserted into the correct slot.
2. Remove the module cover screw.
3. Remove the top cover by sliding it towards the rear and then lift it upwards.
4. Set the timing selection switches (channel 1, channel 2) to the desired timing modes.
5. Replace the top cover and the cover screw.
3-30
SETTINGS
G.703
channel 1
Surge
G.703
channel 2
Surge
Figure 3–31: G.703 INTERFACE CONFIGURATION
1a
X
Shld.
X 1b
Tx -
G.703
2a
Rx - X
CHANNEL 1
X 2b
Tx +
3a
X
Rx +
X 3b
SURGE
6a
Shld. X
X 6b
Tx -
G.703
7a
Rx - X
CHANNEL 2
X 7b
Tx +
8a
Rx + X
X 8b
SURGE
B90 Low Impedance Bus Differential System
 
PRODUCT SETUP DIRECT I/O
1a
X
Shield
X 1b
Tx –
X 2a
Rx –
X 2b
Tx +
X 3a
Rx +
X 3b
X 6a
Shield
X 6b
Tx –
7a
Rx – X
X 7b
Tx +
8a
X
Rx +
8b
X
842773A2.CDR
1a
X
Shld.
X 1b
Tx -
G.703
2a
X Rx -
CHANNEL 1
X 2b
Tx +
3a
X
Rx +
X 3b
SURGE
6a
X Shld.
X 6b
Tx -
G.703
7a
X Rx -
CHANNEL 2
X 7b
Tx +
8a
X Rx +
X 8b
SURGE
831727A3.CDR
3 HARDWARE
3.3.4 G.703 INTERFACE

DIRECT I/O DATA RATE
GE Multilin