RAD Data comm ASM-10/8 operation manual Receiver Remote Power Failure RPF Indication Diagnostics

Receiver

Remote Power

Failure (RPF)

Indication

V.54 Diagnostics

The receiver comprises several circuits, as shown in the block diagram, Figure 1-6.

•The receive filter removes all the out-of-band frequencies.

•The automatic equalizer comprises several equalizers which are activated according to baud rate.

•The digital AGC automatically compensates for the attenuation of the line.

The Remote Power Failure feature notifies the user at a central location of a power failure in a remote modem.

The remote power failure feature can be configured only when the ASM-10/8 standalone unit (remote) operates in conjunction with the rack-mounted card ASM-10/8/R (central). When a power failure occurs, ASM-10/8 standalone unit transmits a special tone, which is detected by the ASM-10/8/R and causes the RPF LED to turn on. A special push button

–RPF – located on the front panel of ASM-10/8/R, allows the user to reset the RPF LED. The RPF jumper in the standalone unit enables or disables the feature. RPF should be disabled for multipoint applications.

ASM-10/8 features V.54 diagnostic capabilities for performing local analog loopback and local and remote digital loopback. When the modem is set to the digital loopback mode, the operator at either end of the line can test both modems and the line. The loopback is controlled either with front-panel push buttons or via pin 18 and pin 21 of the V.24/RS-232 interface.

A selectable option allows insertion of a delay into the data stream so that the V.54 loops are not carried across the network.

A selectable option allows insertion of a delay into the data stream so that the V.54 loops are not carried across the network. The delay prevents the last modem from receiving the complete V.54 data sequence and, in turn, being induced into the loop. V.54 delay is required only when operating in synchronous mode.