Printronix L5020 - Manual (Page 79)

Serial Parameters (RS-232 And RS-422)
79
RTS Polarity
Values: Normal (default) or Inverted.
This parameter must be set to match the RTS signal polarity of your
host computer.
This parameter enables the RTS signal to invert if required for a
particular installation.
Buffer Size
Value: 8192 bytes.
This parameter reflects the size in characters of the printer’s data
buffer.
This parameter cannot be changed in the current release of the
emulation software. However, it might be changeable in a future
release.
Number (Of) Buffers
Value: 2.
This parameter reflects the number of data buffers in the printer’s
memory.
This parameter cannot be changed in the current release of the
emulation software. However, it might be changeable in a future
release.
FIFO Trigger
Values: None, 1, 4, 8, or 14 (default).
You can specify how many bytes the First In, First Out (FIFO) input
buffer stores before the bytes are sent to the printer’s data buffer.
Diagnostic
Values: None (default), Transmit, or Loopback.
This parameter provides for testing of the serial interface circuits.
Tests include a data transmission test and a serial loopback test
(which requires a loopback plug).