Comtech EF Data SMS-458B User Manual
Page 7
SMS-458B Modem Protection Switch
Revision 2
Preface
MN/SMS458B.IOM
v
CHAPTER 4. THEORY OF OPERATION .................................................................. 4–1
4.1 Monitor and Control....................................................................................................................................4–1
4.1.1 General....................................................................................................................................................4–1
4.1.2 Description of Options............................................................................................................................4–2
4.1.2.1 M&C Serial Interface ......................................................................................................................4–2
4.1.2.2 Remote Baud Rate...........................................................................................................................4–3
4.1.2.3 Remote Address ..............................................................................................................................4–3
4.1.2.4 External Remote Serial Interface Selection .....................................................................................4–4
4.1.2.5 Battery .............................................................................................................................................4–4
4.1.2.6 Error Response Switch ....................................................................................................................4–5
4.1.2.7 External I/O Interrupt Arbitration ...................................................................................................4–5
4.1.3 Modem Control Interface Specification..................................................................................................4–5
4.1.4 Relay-Remote Interface Specification ....................................................................................................4–6
4.1.4.1 Scope ...............................................................................................................................................4–6
4.1.4.2 General ............................................................................................................................................4–6
4.1.4.3 Command Structure.........................................................................................................................4–6
4.1.5 Fault Interface Specification ...................................................................................................................4–9
4.1.5.1 Controller Fault .............................................................................................................................4–10
4.1.5.2 M:N Fault ......................................................................................................................................4–10
4.1.5.3 Demodulator Signal Fault..............................................................................................................4–10
4.1.6 Online Status Specification...................................................................................................................4–10
4.1.7 Monitor and Control Theory of Operation ...........................................................................................4–11
4.2 Interface Switches ......................................................................................................................................4–11
4.2.1 IDR/G.703 Interface Switch .................................................................................................................4–11
4.2.1.1 General Description.......................................................................................................................4–11
4.2.1.2 Specification (IDR/G.703) ............................................................................................................4–12
4.2.1.3 Connector Pinout...........................................................................................................................4–13
4.3 Address Decoder/Driver ............................................................................................................................4–15
4.3.1 General..................................................................................................................................................4–15
4.3.2 Specifications........................................................................................................................................4–16
4.3.3 Address Decoder/Driver Theory of Operation .....................................................................................4–17
4.4 IF Switch Driver.........................................................................................................................................4–18
4.5 Data Switch Controller Card ....................................................................................................................4–19
4.6 IF Switch .....................................................................................................................................................4–20
4.6.1 General..................................................................................................................................................4–20
4.6.2 Specifications........................................................................................................................................4–20
4.6.3 IF Switch Theory of Operation.............................................................................................................4–20
4.7 Online Telemetry........................................................................................................................................4–22
4.7.1 General..................................................................................................................................................4–22
4.7.2 Specifications........................................................................................................................................4–22
4.7.3 Online Telemetry Theory of Operation ................................................................................................4–22