Printronix SL4M - Manual (Page 129)

INTERFACES Submenus
129
Parallel Port
• Port Type . This menu item selects the type of printer parallel port
interface to be used with the host.
The options are IEEE 1284 (factory default), Disable, and Centronics.
• Data Bit 8
• Enable (factory default). The PI line is not passed directly from host
to printer; all 8 bits are used for data bits, and characters in the hex
80-FF range can be accessed.
• Disable . When the host PI line is enabled, data bit 8 internally
indicates PI line status. To use the PI line, disable data bit 8, and
enable the Host PI configuration option (under the PI Ignored option).
NOTE: Data bit 8 is interpreted as either data bit 8 or PI signal, but never
both. When enabled as data bit 8, data bit 8 has priority over the PI
signal, and all data above hex 7F is used to access character data
and not to interpret PI line data.
Conversely, when data bit 8 is disabled and the PI signal is used, data
bit 8 of the data is reserved for use as the PI function, and you cannot
access characters in the hex 80-FF range. Therefore, to access
characters in the hex 80-FF range, data bit 8 must be enabled.
• PI Ignored . The PI (Paper Instruction) signal is used to control vertical
paper motion.
• Enable (factory default). Ignores the PI signal and treats the data as
characters or control codes.
• Disable . Causes the printer to interpret the eight data lines as VFU
commands when the PI signal is true.
• Buffer Size in K . This option configures the amount of memory allocated
for the Ethernet buffer. The range is 1-16 Kbytes, in 1-Kbyte increments.
The factory default is 16 Kbytes.
• Auto Trickle. This feature is used to prevent a host computer from
“timing out” because the parallel interface is “busy” for too long.
• Disable (factory default). The Auto Trickle feature is not used.
• Enable . When the printer’s buffers are almost full, the printer begins
to trickle data in from the host (at the rate set in the Trickle Time
menu) until the buffers start to empty out.
• Trickle Time . When the printer is printing data from a host and a second
print job is received by the printer from a different host, Trickle Time
prevents the second host from timing out while it is waiting for its data to
be printed. In order to support this feature, the port has to be able to
accept data from the host and store it for future use.
For example, if the printer is printing a job from the serial port, and then
receives a second print job from the parallel port, the data from the
parallel port will “trickle” bit by bit into the printer buffer to prevent a
timeout error from being sent back to the host connected to the parallel
port.