DS2155 datasheet(59/238 Pages) DALLAS

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DS2155

59 of 238

10.2 Automatic Alarm Generation

The device can be programmed to automatically transmit AIS or remote alarm. When automatic AIS

generation is enabled (E1TCR2.1 = 1), the device monitors the receive-side framer to determine if any of

the following conditions are present: loss-of-receive frame synchronization, AIS alarm (all ones)

reception, or loss-of-receive carrier (or signal). The framer forces either an AIS or remote alarm if any

one or more of these conditions is present.

When automatic RAI generation is enabled (E1TCR2.0 = 1), the framer monitors the receive side to

determine if any of the following conditions are present: loss-of-receive-frame synchronization, AIS

alarm (all ones) reception, loss-of-receive carrier (or signal), or if CRC4 multiframe synchronization

cannot be found within 128ms of FAS synchronization (if CRC4 is enabled). If any one or more of these

conditions is present, then the framer transmits an RAI alarm. RAI generation conforms to ETS 300 011

specifications and a constant remote alarm is transmitted if the DS2155 cannot find CRC4 multiframe

synchronization within 400ms as per G.706.

Note: It is an invalid state to have both automatic AIS generation and automatic remote alarm generation

enabled at the same time.

DS2155 Datasheet(PDF) 59 Page - Dallas Semiconductor