Serial Interface Unit User's Manual

8
Technical Specifications (Input)
Interface: RS-232C-level
Synchronization: Asynchronous
Baud rate: 300, 600, 1200, 2400, 4800, 9600, 19200 BPS
(selectable)
Word length
Start bit:2 1
Data bits: 7 or 8 (selectable)
Parity bit: Odd, even, none (selectable)
Stop bits: More than one bit
Signal polarity
Mark: Logical 1 (–3V to –15V)
Space: Logical 0 (+3V to +15V)
Handshaking: DTR, XON/XOFF
Connector Signals and Functions
Pin No. Signal Name Direction Function
1 F - GND — Printer chassis ground
2 TXD OUT Data from printer
3 RXD IN Data to printer
4 RTS OUT Always SPACE
5 CTS — Not checked by printer
6 NC Not used
7 S - GND — Signal ground
8 - 10 NC Not used
11 RCH OUT Same signal as pin 20
12 - 19 NC Not used
20 DTR OUT SPACE when printer ready to receive
21 - 25 NC Not used