GE B30 Instruction Manual page 92

3.3 DIRECT INPUT AND OUTPUT COMMUNICATIONS
For the looped timing mode, the system clock is derived from the received line signal. Therefore, the timing selection
should be in loop timing mode for connections to higher order systems.
The C37.94SM communications module cover removal procedure is as follows:
1. With power to the relay off, remove the C37.94SM module (modules 2A or 2B) as follows. Record the original location
of the module to help ensure that the same or replacement module is inserted into the correct slot.
2. Simultaneously pull the ejector/inserter clips located at the top and at the bottom of each module in order to release the
module for removal.
3. Remove the module cover screw.
4. Remove the top cover by sliding it towards the rear and then lift it upwards.
5. Set the timing selection switches (channel 1, channel 2) to the desired timing modes (see description above).
6. Replace the top cover and the cover screw.
7. Re-insert the C37.94SM module. Take care to ensure that the correct module type is inserted into the correct slot
position. The ejector/inserter clips located at the top and at the bottom of each module must be in the disengaged posi-
tion as the module is smoothly inserted into the slot. Once the clips have cleared the raised edge of the chassis,
engage the clips simultaneously. When the clips have locked into position, the module is fully inserted.
3-40
Figure 3–45: C37.94SM TIMING SELECTION SWITCH SETTING
B30 Bus Differential System
3 HARDWARE
GE Multilin