Receiving & Installation 3-7MN1854
RS–232 PC Connections
A null modem connection must be made between the LinStep+ and the computer
COM port. This will ensure that the transmit and receive lines are properly
connected. Either a 9 pin or a 25 pin connector can be used at the computer,
Figure 3-6. Maximum recommended length for RS232 cable is 6 ft. (1.8 meter).
Figure 3-6 9 & 25 Pin RS-232 Cable Connections for UL Installations
25 Pin Connector
9 Pin Connector
Pin Signal
2 RXD
3 TXD
7 GND
Pin Signal
2 RXD
3 TXD
5 GND
LinStep+
(DCE)
Computer
COM
Port
(DTE)
RXD– 4
TXD – 5
Com – 6
RXD
TXD
GND
RS232 Connector
Chassis
If required, RTS, CTS, DSR and DTR may also
be connected for a full null modem connection.
Jumper 9 Pin 25 Pin
RTS to CTS
DSR to DTR 7 to 8
4 to 6 4 to 5
6 to 20
Tx
Com
N/A
Rx
N/A
N/A
Connector location is
shown in Figure 3-4.
Figure 3-7 9 & 25 Pin RS-232 Cable Connections for CE Installations
Control
(DCE)
Computer
COM
Port
(DTE)
RXD
TXD
GND
RXD
TXD
GND
PE PE
RS232 Connector