6100 BSC Programming Manual

6100 BSC Link and Station Management
On a half duplex line, BSC lowers RTS as soon as the write is
complete, for instance, right after transmitting the ACK as
part of the READ request.
Clear to Send (CTS)
BSC waits for this signal before starting to transmit, and
expects the signal to stay on throughout the transmission. If
CTS drops during a transmission, the transmission stops and a
modem error (status code 140) is reported; the status detail
field tells which signal was lost. BSC does not retry the
request.
BSC monitors the state of CTS only before and during a
transmission. Therefore, the modem may keep CTS on at all times.
Data Carrier Detect (DCD)
BSC waits for this signal before starting to read. If DCD
drops while BSC is reading, the read stops and BSC retries
the request. If retries are exhausted before DCD returns,
BSC reports a modem error (status code 140); the status
detail field tells which signal was lost.
BSC monitors the state of DCD only before and during a read.
Therefore, the modem may keep DCD on at all times. If the
line is switched, DCD should be on at all times.
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