Rs-422; Rs-232 Serial Interface Protocols - IBM 6400 Setup Manual

Receive Data (RD). Serial data stream to the printer.
Clear To Send (CTS). Status signal to the printer indicating the host is ready
to receive data/status signals from the printer.
Data Set Ready (DSR). Status signal to the printer indicating the host is in a
ready condition.
Data Carrier Detect (DCD). Status signal to the printer. The ON condition is
required for the printer to receive data.
Transmit Data (TD). Serial data stream from the printer for transmitting status
and control information to the host. Subject to protocol selection.
Request To Send (RTS). Control signal from the printer. Subject to
configuration.
Data Terminal Ready (DTR). Control signal from the printer. Subject to
configuration.

RS-422

Table 6. RS-422 Serial Interface Connector Pin Assignments
Input Signals
Signal Pin
- Receive Data 15
(-RD)
+ Receive Data 17
(+RD)
+RD, -RD.Serial data stream differentially received by printer.
+TD, -TD.Differentially driven serial data stream for transmitting status and
control information to the host. Subject to protocol selection.
± ±
NOTE: RD and TD form signal and return paths of a differential line signal.

RS-232 Serial Interface Protocols

DTR. (DTE Ready). The printer controls the data flow by asserting or de-
asserting this hardware signal to the host. If there is enough room in the
printer buffer, the printer will send a high signal; if the buffer is full the printer
will send a low signal. DTR tells the host if it is safe to send more data (If the
host sends data during an unsafe condition, data will be lost.
Output Signals
Signal Pin
- Transmit Data 19
(-TD)
+ Transmit Data 25
(+TD)
RS-422
Miscellaneous
Signal Pin
Chassis Ground 1
Signal Ground 7
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