Comtech EF Data SDM-100A - Manual (Page 142)

Theory of Operation SDM-100A Satellite Modem
4–26 Rev. 0
4.4.4 Asynchronous Interface
Refer to Appendix B.
4.4.5 Terrestrial Interface Change
The modem comes configured for one specific type of interface. To convert to another
interface type, a field change is required. Since the modem interface module is a daughter
card that plugs onto the demodulator board, it will be necessary to remove the top cover
of the modem to make an interface change.
The interface daughter cards are as follows:
Interface Daughter
Card
RS-422 AS/2524
V.35
34-pin
25-pin
AS/2532
AS/4326
RS-232-C AS/2533
To change the interface daughter card:
1. Remove the modem top cover.
2. Remove the six screws in the top of the interface daughter card at the rear of the
unit.
3. Unplug the daughter card from the Demodulator/M&C/Interface board.
4. Replace the interface with a new daughter card, and replace the six screws.
5. Replace the modem top cover, and re-install the modem into the system.