Serial Interface Signals - Texas Instruments 880 User Manual

Table 7-3. Serial Interface Signals
Pin
No. Source Signal RS232 CCITT
Function
PROTECTIVE GND AA 101 Connected to earth ground.
2 P TRANSMITTED DATA BA 103 Conveys data to host.
3 H
RECEIVED DATA
BB 104
Conveys data to printer.
4 P REQUEST TO SEND CA 105 CNFG.CODE 14 or 15 ON: ON at
all times.
CNFG.CODE 13 ON: ON when
printer on line;
OFF when printer is off line.
5 H *CLEAR TO SEND CB 106 CNFG.CODE 14 or 15 ON: Not
used.
CNFG.CODE 13 ON: Must be ON
to send data.
6
H *DATA SET READY CC 107 Must be ON to send/receive data.
7 SIGNALGND AB 102 Ground reference for interface
signals.
8 H
*RECEIVED LINE CF
109
CNFG.CODE 140r 15 ON: Not
SIGNAL DETECTOR
used.
CNFG.CODE 13 ON: Must be on
to receive data.
9
P
+
VOLTS
+
12 Vdc Input bias; tied to 1 K
series resistor.
10 P -VOLTS
-12 Vdc Input bias; tied to 1 K
series resistor.
11 P READY/BUSY Signals READY/BUSY status to
host;
READY ION when CNFG.CODE
13, 14, or 16 enabled;
READY /OFF when CNFG.CODE
15 enabled.
20 P
DATA TERMINAL
CD
108.2 CNFG.CODE 14 or 15 ON: ON all
READY
the time;
CNFG.CODE 13 ON: ON when on
line; OFF when off line.
Same as READY /BUSY when
CNFG.CODE8AON.
P
=
Printer
H
=
Host
Pins 12-19and21-25are not used.
* Biased on with no connection.
7-4