Serial Interface; Appendix B Status Page; Serial Interface Specifications - Mita DP-2800 Service Manual

Serial interface

The printer is equipped with a serial port whose circuitry duplicates the option interface card.
The device responsible for controlling the serial interface is integrated in the gate array in the
controller system. The serial interface supports both protocols of RS-232C and RS-422A.
In the RS-232C protocol, CTS and DSR signals are included to support SNMP (Simple
Network Management Protocol) protocol (used typically for Windows 95's plug-and-play
function). Toggling the protocol between RS-232C and RS-422A is made by a shorting
jumper socket that is accessible on the controller board. (The jumper wire arrangement, that
used to be provided for the succeeding models to switch the DTR polarity is not used with
these models.) To change the serial interface protocol, refer to Changing the serial interface
configuration section which follows.
A 25-pin D-sub connector is used for the serial interface. The extra signals used for
RS-422A are assigned to these pins that are not used for RS-232C according to the IBM
pin assignment scheme.

Serial interface specifications

The table below summarizes the specifications for the serial interface used in the printer.
The parameter options can be selected using either the printer's front panel or Prescribe
FRPO command.
Item
1
Interface mode*
Baud rate
Data bit length
Parity bit length
2
Protocol*
Error robust
3
control*
Status send
*1 The serial interface mode currently engaged is indicated at the bottom of the service
status page as: RS2 = RS-232C mode, RS4 = RS-422C mode.
*2 In the protocols that do not use DTR, DTR is fixed to be positive.
*3 Robust: Xon is sent every 3 to 5 seconds during ready or waiting. Error Control: Sets
the printer off line when an error occurs or at off line state.
Option parameters
RS-232C or RS-422C
300, 600, 1200, 2400,
4800, 9600, 19200,
38400, 57600, 115200
7, 8
None (0), odd (1), even (2), Front panel or FRPO
ignore (3)
DTR [pos] & Xflow [buf] (0), Front panel [(1) through
DTR [pos] (1), DTR [neg]
(2), Xflow [buf] (3), ETX
[nobuf] (4), Xflow [nobuf]
(5), ETX [buf] (6), Xflow
[buf] & ETX [nobuf] (7)
Robust On (0), Robust
Off (1), Error Control &
Robust Off (10), Error
Control & Robust On (11)
^C, ^T, Esc.B, Esc.
Selection
By changing hardware
jumper (See the next
section)
Front panel or FRPO
H1 command
Front panel or FRPO
H2 command
H4 command
(4) only] or FRPO H5
command
FRPO D0 command
5A2
Default
RS-232C
(factory
setting)
9600 (96)
8
None (0)
DTR [pos]
& Xflow
[buf] (0)
Robust On
(0)
A-3