User guide

B-1
APPENDIX B. 9 PIN SERIAL INPUT/OUTPUT
B.1 PIN DESCRIPTION
All external communication peripherals
connect to the CR10 through the 9-pin
subminiature D-type socket connector located
on the front of the Wiring Panel (Figure B-1).
Table B-1 shows the I/O pin configuration,
and gives a brief description of the function of
each pin.
FIGURE B-1. 9 Pin Connector
TABLE B-1. Pin Description
ABR = Abbreviation for the function name.
PIN = Pin number.
O = Signal Out of the CR10 to
a peripheral.
I = Signal Into the CR10 from
a peripheral.
PIN ABR
I/O Description
1 5V O 5V: Sources 5V DC,
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
CR10 in the
telecommunications
mode.
4 RXD I Receive Data: Serial
data transmitted by a
peripheral are received
on pin 4.
5 ME O Modem Enable: Raised
when the CR10
determines that a
modem raised the ring
line.
PIN ABR
I/O Description
6 SDE O Synchronous Device
Enable: Used to address
Synchronous Devices
(SDs), and can be used
as an enable line for
printers.
7 CLK/ I/O Clock/Handshake: Used
HS with the SDE and TXD
lines to address and
transfer 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 TE O Tape Enable: Powers the
cassette recorder during
tape transfer.
9 TXD O Transmit Data: Serial
data are transmitted from
the CR10 to peripherals
on pin 9; logic low marking
(0V) logic high spacing
(5V) standard
asynchronous ASCII, 8
data bits, no parity, 1 start
bit, 1 stop bit, 300, 1200,
9600, 76,800 baud (user
selectable).