Appendix A. CS I/O 9 Pin Serial Port

TABLE A-1. Pin Description

ABR = Abbreviation for the function name.

PIN

= Pin number.

 

O

= Signal Out of the datalogger to a peripheral.

I

= Signal Into the datalogger from a peripheral.

 

 

 

 

 

PIN

 

ABR

I/O

Description

 

 

 

 

 

1

 

5V

I

5 VDC supply. Not used.

 

 

 

 

 

2

 

SG

 

Signal Ground: Provides a power return for pin 1

 

 

 

 

(5V), and is used as a reference for voltage levels.

 

 

 

 

 

3

 

RING

O

Ring: Raised by the modem to put the datalogger

 

 

 

 

in the telecommunications mode.

 

 

 

 

 

4

 

RXD

O

Receive Data: Serial data transmitted by the

 

 

 

 

modem are transmitted on pin 4.

 

 

 

 

 

5

 

ME

I

Modem Enable: A logic high internally switches

 

 

 

 

power to the modem. A logic low internally

 

 

 

 

powers down the modem.

 

 

 

 

 

6

 

SDE

I

Synchronous Device Enable: A logic high disables

 

 

 

 

communication with the modem, without removing

 

 

 

 

power or changing the modem’s mode.

 

 

 

 

 

7

 

Clock/

I/O

Clock/Handshake: Used with the SDE and TXD

 

 

HS

 

lines to communicate with devices that address it.

 

 

 

 

 

8

 

TE

I

+12 VDC power supply.

 

 

 

 

 

9

 

TXD

I

Transmit Data: Serial data are transmitted from

 

 

 

 

the datalogger to the modem 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).

 

 

 

 

 

A-2