11.4 PDH Functions > E1 Frame Words
This function requires the E1 signal to be framed. The NFAS word is used to carry information about the status of the link and to
provide control signals for primary rate multiplexers.
- Bit 1: Reserved for International use (M is used to transmit the CRC multiframe signal in PCM30C and PCM31C)
- Bit 2: Set to “1” to prevent simulation of FAS
- Bit 3: A shows the remote alarm indication
- Bits 4 to 8: Sa4 to Sa8 are spare bits.
Tx:
Bits Sa4 to Sa8 are used to send optional network messages. The Sa bits should be set to “1” when they are not used or
when links cross International borders.
Rx:
Bit Sa4 can be used as a message based data link for operations, maintenance and performance monitoring.
TX150 e-Manual D07-00-023 Rev A02
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