10/06
Vision™ OPLC™ Vision120™
6
Unitronics
RS232 to RS485: Changing Jumper Settings
Ports can be set to either RS232 or RS485 according to jumper settings.
To access the jumpers, you must open the controller, and then remove the module’s
PCB board. Before you begin, turn off the power supply, disconnect and dismount the
controller.
When a port is adapted to RS485, Pin 1 (DTR) is used for signal A, and Pin 6 (DSR)
signal is used for signal B.
If a port is set to RS485,
and
flow signals DTR and DSR are not used, the port can also
be used to communicate via RS232; with the appropriate cables and wiring.
Before performing these actions, touch a grounded object to discharge any electrostatic
charge.
Avoid touching the PCB board directly. Hold the PCB board by its connectors.
1. Turn power off before opening
the controller.
2. Locate the 4 slots on the sides
of the controller.
3. Using the blade of a flat-bladed
screwdriver, gently pry off the
back of the controller.
4. Gently remove the top PCB
board:
a. Use one hand to hold the top-
most PCB board by its top
and bottom connectors.
b. With the other hand, grasp
the controller, while keeping
hold of the serial ports; this
will keep the bottom board
from being removed together
with the top board.
c. Steadily pull the top board off.
5. Locate the jumpers, and then
change the jumper settings as
required. Jumper settings are
shown on page 7
