Serial Port; Serial Port Features; Serial Port Pin Out; Table 22 Serial Bit Rates - TransAct Ithaca 90PLUS Series Programmer's Manual

Programmer's Guide

8.3 Serial Port

8.3.1

Serial Port Features

The serial port features are as follows:
Baud rates
Bit patterns
Flow control

Table 22 Serial bit rates

It should be noted that the 7-bit no parity is in fact an 8-bit format. The implementation of the hardware
UART in the Intel 8051 family will not implement a true 7-bit no parity format. If the host provides a true
7-bit no parity format, it must be configured with two stop bits.
The Series 90PLUS Printer has a 64-character high-speed buffer before the main system buffer. This high-
speed buffer allows the printer to operate at high serial data rates while printing. Because no data is
evaluated in this buffer, the printer will have a delayed response to inquire requests and [CR]'s during one-
line operation. This has a significant effect on one-line mode operation.
8.3.2

Serial Port Pin out

Not connected
Used in printer
Output to host
Ready and/or flow
control signal to host
Disable printer
control from host
Ready and/or flow
control signal to host
Flow control from
host
Strapable 12 V or
DTR

Table 23 Serial port pin out

Because both the host and the printer are data terminal equipment (DTEs), they use the same serial port pin
outs. If the cable used to connect the host to the printer is a pin-to-pin interconnect, it will not work. For this
reason, a null modem or turn around cable must be used to interconnect the host and the printer.
11/07/05
PcOS Series 90PLUS
300, 600, 1200, 2400, 4800, 9600, 19.2 K
8-bit no parity; 8-bit odd; 8-bit even; 7-bit no parity; 7-bit odd; 7-bit even
DTR and XON/XOFF
Input Pin 1 DCD Data carrier detect
Input Pin 2 RX Receive data
Output Pin 3 TX Transmit data
Output Pin 4 DTR Data terminal ready
Pin 5 GND Signal ground
Input Pin 6 DSR Data set ready
Output Pin 7 RTS Request to send
Input Pin 8 CTS Clear to send
Output Pin 9 SSD Secondary data
Rev Q
Communications
Serial Port
Not used
Commands/data to print
Return data
Printer ready to receive data
(follows buffer)
Not used in standard printer
(configurable)
Printer ready to receive data
(follows buffer)
Not used in standard printer
(configurable)
Not used in standard printer
(provides power to peripheral)
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