User`s manual

Technical Information
terminal is ready to receive data, OFF - indicates the data terminal is not ready to
receive data.
If the Rec.Flow option has been set to xon/xoff, the Request-to-Send signal is
ignored.
Pin 5 — Clear-to-Send (CB)
For data modes other than Mode 2, the Clear-to-Send circuit is controlled by the
ADM to indicate when data can be received from the data terminal. If the
trans.flow option (Transmit Flow Control option) has been set to eia, Clear-to-
Send is used for flow control as follows: ON - the ADM is ready to receive data,
OFF - the ADM is not ready to receive data. For Mode 2, this transmit flow
control operation applies when the physical EIA port speed is higher than the
current channel throughput (handshake) speed.
Pin 6 — Data Set Ready (CC)
Data Set Ready is ON while power is available.
Pin 7 — Signal Ground (AB)
This circuit provides the common reference level for all signals at this interface.
Signal ground is direct current isolated from the power source.
Pin 8 — Received Line Signal Detect (CF)
This circuit indicates the presence of a data call connection. If the DCD option is
set to IGNORE, the Received Line Signal Detect circuit is ON while power is
available, turning OFF for one second after a call has been cleared. If the DCD
option is set to FOLLOW, the signal on this circuit is ON after a call has been
connected and goes OFF once the call has been cleared.
Pin 20 — Data Terminal Ready (CD)
This circuit allows the attached terminal to control the ADMs connection to the
network. When the DTR option is set to FOLLOW, the ADM requires an ON
condition to interact with the attached terminal or to initiate or maintain a data
connection or test sequence (except the local self-test). If the attached terminal
drops DTR for more than 50 milliseconds during data call setup, while in the data
transfer mode, or during a test sequence, the ADM clears the call or terminates
the test.
When the DTR option is set to IGNORE, the ADM ignores the DTR lead. Thus,
dropping the DTR lead will not cause a call to be cleared.
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