Appendix B. Serial Port Pinouts 
B.1  CS I/O Communication Port 
Pin configuration for the CR800 CS I/O port is listed in table Pinout of CR800 CS 
I/O D-Type Connector Port 
(p. 553). 
 
 
 Pinout of CR800 CS I/O D-Type Connector Port 
Pin 
Number 
Function 
Input (I) 
Output (O) 
Description 
1  5 Vdc  O 
5 Vdc: sources 5 Vdc, used to power 
peripherals. 
2  SG   
Signal ground: provides a power return 
for pin 1 (5V), and is used as a reference 
for voltage levels. 
3  RING  I 
Ring: raised by a peripheral to put the 
CR800 in the telecoms mode. 
4  RXD  I 
Receive data: derial data transmitted by a 
peripheral are received on pin 4. 
5  ME  O 
Modem enable: raised when the CR800 
determines that a modem raised the ring 
line. 
6  SDE  O 
Synchronous device enable: addresses 
synchronous devices (SD); used as an 
enable line for printers. 
7  CLK/HS  I/O 
Clock/handshake: with the SDE and 
TXD lines addresses and transfers data to 
SDs. When not used as a clock, pin 7 can 
be used as a handshake line; during 
printer output, high enables, low 
disables. 
8  +12 Vdc   
Nominal 12 Vdc power. Same power as 
12V and SW12 terminals. See    TABLE: 
Current Source and Sink Limits 
(p. 389). 
9  TXD  O 
Transmit data: transmits serial data from 
CR800 to peripherals on pin 9; logic-low 
marking (0V), logic-high spacing (5V), 
standard-asynchronous ASCII: eight data 
bits, no parity, one start bit, one stop bit. 
User selectable baud rates: 300, 1200, 
2400, 4800, 9600, 19200, 38400, 
115200.