Comtech EF Data OM20 - Manual (Page 44)

OM20 Universal Outdoor Modem OM20 Theory of Operation
MN-OM20– Revision 5 4–6
4.3 Monitor & Control (M&C) Subsystem
The modems M&C system is connected to most of the circuitry on any board contained in the
modem. These connections provide status on the working condition of the circuitry as well as
providing the data required for the various measurements the modem provides. The M&C
processes this information and generates status indications as well as alarms when necessary.
Detailed status information is available via the modems various user interfaces including the
remote and terminal ports. An external summary fault is available on the RS422 Data interface
The M&C contains a high-performance microprocessor and is responsible for overall command
and control of modem functions. The M&C is constantly monitoring all subsystems of the
modem by performing a periodic poll routine and configures the modem by responding to
commands input to the system. During each poll cycle, the status of each of the subsystems is
collected and reported to each of the external ports. Performance statistics such as Eb/No, buffer
fill %, etc. are compiled. If faults are detected, the M&C will take appropriate actions to
minimize the effect of such faults on the system.
The modem supports the following M&C protocols:
 Terminal Interface (Section 4.2.1)
 Remote Port Interface (RLLP) (Section 4.2.2)
 Ethernet M&C, Web Browser & SNMP (Section 4.2.3)
 Modem Status, Alarms & Contact Closures (Section 4.2.4)