Printronix L5020 - Manual (Page 221)

RS-232 Serial Interface
223
RS-232 Serial Interface Signals
The RS-232 serial interface signals are defined below.
Receive Data (RxD) - Serial data stream to the printer.
Transmit Data (TxD) - 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.
Clear To Send (CTS) - Status signal to the printer indicating the
host is ready to receive data/status signals from the printer. When
CTS is enabled, DSR and CTS must both be asserted for the
printer to transmit flow control characters to the host.
Data Set Ready (DSR) - Status signal to the printer indicating the
host is in a ready condition. DSR is ignored unless CTS or CD are
enabled.
Carrier Detect (CD) - Status signal to the printer. The ON condition
is required for the printer to receive data. Available as a
configuration setup option.
When CD is enabled, the host must
assert both DSR and CD for the printer to accept data.
Data Terminal Ready (DTR) - Control signal from the printer to the
host. When enabled, the host activates the data channel. Subject to
configuration.