Table 2-1. Interface Signal Descriptions

TM 11-7010-207-23

Table 2-1.

Interface Signal Descriptions

Description

RS-232-C

Signal Name

Chassis ground. Isolated from signal

F.G. (Protective Ground

or Earth)

ground or common return.

Common signal and dc power ground.

S.G. (Signal Ground or

Isolated from protective ground.

Common Return)

A positive level from the converter with

CTS (Clear to Send)

a selectable delay, after receipt of

Request to Send and when the converter is

ready to transmit.

A positive level to the converter when

RTS (Request to Send)

data transmission is desired.

A positive level from the DCE or DTE

RLSD (Received Line

that is used to indicate that the

Signal Detector)

terminal is active.

RD (Receive Data)

Serial digital data at the output of the

converter receiver. Circuit BB is held

in the mark condition whenever circuit CF

(RLSD) is in the OFF (negative voltage)

condition.

Serial digital data from a data terminal

TD (Transmitted Data)

or other digital data source. The

terminal equipment shall hold circuit BA

in the mark (negative voltage) condition

during non-data intervals.

A positive level from the converter when

DSR (Data Set Ready)

power is on. Circuit CC will be in the

OFF condition if the DCE is in a

self-test mode ( loopback).

2-3. ASYNCHRONOUS TRANSMISSION

The 600GR converter is an asynchronous limited-distance modem designed to transmit

digital data between terminals and/or computers up to 2 kilometers apart.

Asynchronous transmission is sometimes called start-stop transmission. Each

transmitted character begins with a one bit start element. Start sense is binary O

(space). The 7-bit character and parity bit is followed by a stop element having

binary 1 (mark sense). The interval between the stop element of a character and

the start element of the next character may be of any duration. During this

interval, the converter maintains the stop element sense (mark). It operates at

any data rate up to 9600 bps to meet the characteristics of the transmitted data

stream.

2-2