Avaya 555-233-116 User Manual
Page 59
Connect data modules
Issue 4 October 2002
59
555-233-116
Adjusting the control-panel display on the 7400A
1. Adjust the contrast of the display so that you can see it comfortably. Press
the ENTER/YES button. This steps you through the available contrast
settings.
7400A data module, EIA RS-232 interface circuits
The data module communicates with other equipment through a configurable, 25-
pin RS-232 serial interface. DCE and DTE operation use different sets of pins and
assign different functions to some of the same pins. To avoid confusion later on,
please take a moment to review the differences. See the table below (the pins
most discussed in subsequent sections have been emphasized).
D
T
R
D
S
R
R
I
D
C
D
R
T
S
C
T
S
T
D
R
D
HOME
POWER
TEST
0
0
—
0
0
0
—
—
DATA
NEXT/NO
BACK
ENTER/YES
✹
7400A Data Module
✹
❍
❍
❍
0
0
—
0
0
0
—
—
DATA
NEXT/NO
BACK
ENTER/YES
●
❍
❍
➜ ●
Push the button indicated by the arrow (
➜
)
Pin
Name
Function
DCE
DTE
1
— Not
used
—
—
2
BA (TD)
Transmitted Data
Input
Output
3
BB (RD)
Received Data
Output
Input
4
CA (RTS)
Request to Send
Input
Output
5
CB (CTS)
Clear to Send
Output
Input
6
CC (DSR)
Data Communication Equipment Ready
Output
Input
7
AB (SG)
Signal Ground
Common
Common
8
CF (RLSD)
Received Line Signal Detector
Output
Input
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