AT&T 610 - Modem Port

User's Guide
August 1985
Mode. Port
r
TERMINAL EQUIPMENT
NAME
PROTECTIVE
GROUNO
TERMINAL
SIGNAL
GROUND
I/O
PORT
TRANSMITTED
DATA
... RECEIVED DATA
.... REQUEST TO SEND·
L..CLEAR TO SEND
I .....
OATA
rERMINAL REAOY
L.. DATA SET READY
~DATA CARRIER DETECT
~ SPEED INDICATOR
... SPEED SELECT
"I" COMMUNICATION EQUIPMENT l
PIN
NUMBER CIRCUITS
I
AA
MODEM
AB
fTRANSiiiffiNGl
7
BA
......
I SIGNAL
2
L ...£C!.N!~!.E.!U
BB
F
3
CA
•
iRECETvTNi-l
4
CB
...
I SIGNAL
~
LE~N~~.!~J
CO
•
~
CC
...
~
CF
~
SI
~
SS
......
~
...
Figure 9-7. Mode. Cable Leads
COMMUNICATION
CHANNEL
..
..
....
....
Table 9-A. 1Iod_ (I/O) Port Interface Pins
Co_unieations
Page 9- 5
Pin 1 Protective Ground -- equipment frame and ac power ground
Pin 2 Transmitted Data (SD) -- data originated by terminal,
binary to modem, analog from modem
Pin 3 Received Data (RD) -- data originated at remote sender,
analog to modem, binary to terminal
Pin 4 Request to Send (RTS) -- signal to modem indicating
ready to transmit -- always held high when power is on
Pin 5 Clear to Send (CTS) -- signal to terminal indicating the
modem is ready to transmit data (ignored by terminal)
Pin 6 Data Set Ready (DSR) -- signal to terminal indicating
the modem is ready to receive or transmit data
Pin 7 Signal Ground -- common ground reference between
terminal and modem
Pin 8 Data Carrier Detect (DCD) -- signal to terminal that
carrier has been detected (ignored by terminal)
Pin 12 Speed Indicator (SI) -- signal from modem (ignored by
terminal)
Pin 20 Data Terminal Ready (DTR) -- signal to modem, always on
except during disconnect and/or power off
Pin 23 Speed Select (SS) -- signal to modem (always off)