The satcom system was not working. The symptom was that the DataStorm Server could not communicate with the dish controller.
I connected the Motosat serial cable to another computer serial port (using a null modem), and used Hyperterm on each PC to test the cable. Although single characters came through okay, characters would get corrupted when typing quickly. When I disconnected the DB9 end on the cable, the DB-9 just pulled off. It's a cheesy cable.
Replaced the cable with one from the Lorreto DataStorm system, and the Satcom system started working.
We tried unsuccessfuly to repair the busted cable.