Comtech EF Data SMS-458B - Manual (Page 83)

SMS-458B Modem Protection Switch Revision 2
Theory of Operation MN/SMS458B.IOM
4–23
4.7 Online Telemetry
4.7.1 General
The online telemetry (Figure 4-10) is a 10.5 x 3.5 inches module that fits into slot 6 of the
upper-front section of the switch chassis. It reports the online status of each prime
modulator and demodulator.
Refer to Figure 4-11 for a block diagram of the online telemetry.
4.7.2 Specifications
Number of Channels 8 modulator and 8 demodulator.
Switching Format Form-C contacts.
4.7.3 Online Telemetry Theory of Operation
The M&C controls the online telemetry module through the address decoder/driver with
an 8-bit data bus and 2 device select lines. Sixteen SPDT relays (Form-C) can be
switched to indicate the online status of 8 prime modulators and 8 prime demodulators.
Note: Only four prime modems may be used with this switch.
Figure 4-10. Online Telemetry