Model 458-3SL (3-Slot Chassis) Rev A
Page 4
3.0 RS-232/Ethernet Controls
RS-232 Connections
The Model 458-3SL is completely controllable from an RS-232 source. The following section
explains the connections and the controls necessary for RS-232 operation. See Figure 2 for an
illustration of the pin connectors.
CONNECTOR DB9
5
9
4
8
3
7
2
6
1
RXD
TXD
CTS/DSR
Figure 2 DB-9 for RS-232 Control
Pin 2 on the Model 458-3SL connects to the RECEIVED DATA pin in the Communications Port
Connector on the PC or controller.
Pin 3 on the Model 458-3SL connects to the TRANSMIT DATA pin in the Communications Port
Connector on the PC or controller.
Pin 5 on the Model 458-3SL connects to the GROUND pin in the Communications Port
Connector on the PC or controller.
Pins 6 and 8 are connected together and held at a positive voltage.
Common Communications Port Connectors, such as those found on PCs, are DB-9 and DB-
25. The standard pin assignments for these connectors are as follows:
DB-9
DB-25
Direction
Received Data
2
3
Serial Data from Model 458-3SL
Transmitted Data
3
2
Serial Data to Model 458-3SL
Ground 5
7
Common
Ground
CTS 8
5
+
Voltage
Out
DSR 6
6
+
Voltage
Out
The remaining pins are not connected to the Model 458-3SL.
