User`s manual

Technical Information
Table 7-1. Interface to Attached Terminal
Pin Direction Function EIA Circuit
Mnemonic
2 To ADM Transmitted Data BA
3 From ADM Received Data BB
4 To ADM Request-to-Send CA
5 From ADM Clear-to-Send CB
6 From ADM DCE Ready CC
7 Signal Ground AB
8 From ADM Received Line Signal Detector CF
20 To ADM DTE Ready CD
22 From ADM Ring Indicator CE
Pin 2 — Transmitted Data (BA)
The ADM receives data from the attached data terminal at 98 to 101 percent of
the selected speed. The data from the attached terminal must have one start bit,
eight information bits, and at least one stop bit. The ADM ignores parity in the
local mode (except for xon/xoff flow control) and transports it transparently in the
data mode. The ADM supports only ASCII-formatted data in the local mode.
The ADM recognizes a BREAK signal as 10 bits of spacing plus
20 milliseconds. The setting of the BREAK option governs the ADMs response
to break in the data mode.
Pin 3 — Received Data (BB)
Signals on this circuit are generated by the ADM in response to data received
from the remote data equipment or to user commands from the data terminal.
This circuit is held in the MARK state when Received Line Signal Detect is OFF
except for user testing and during the Local Mode. The ADM transmits the
BREAK signal as 200 milliseconds of SPACE.
In the data mode, data transmitted to the data terminal consists of one start bit,
eight information bits, and one stop bit. The parity of data received from the
network is transported to the data terminal without alteration, except if requested
to do so by X.29 message from a remote X.25 host.
In the Local Mode, data to the data terminal consists of one start bit, eight ASCII
formatted information bits, and one stop bit. The parity is set as indicated by the
parity option.
Pin 4 — Request-to-Send (CA)
For data modes other than Mode 2, the Request-to-Send circuit can be used by
the data terminal to control data transmission depending on how the Receive
Flow Control option is set. If the rec.flow option (Receive Flow Control option)
has been set to eia, this lead is utilized as follows: ON - indicates the data
7-2