BEWATOR COTAG 4101-2, Installation Handbook, Page: 145 / 158

Fault finding
19-13
One or two controller systems only -
checking the RS232 connections at the controller
Refer to the connection diagrams in the chapter on the 4101 Modular
Controller and check each one carefully. Points to check are:
•
Correct cross-over of TXD to RXD.
•
CTS and RTS linked together at the controller end and not
connected to the PC via the RS232 cable.
•
The RS232 cable should be plugged into CONN1 at the
controller and not CONN2 (the RS485 port!)
Check that the jumpers in the top left corner of the controller
motherboard are set to the correct baud rate to match the rate
selected in the software. This is normally 9600 baud.
The two LEDs next to the RS232 port marked RXD and TXD flash
when messages are received and transmitted, respectively, by the
controller.
If the OUT LED is on continuously then CTS and RTS are not linked
at the controller.
If the TXD LED flashes but there is no activity on the RXD LED when
power is removed and restored at the controller then the TXD and
RXD connections to the PC are probably the wrong way round. Try
reversing them.
Multiple controller systems -
checking the RS232 connections at the Comms module
When a Comms module is installed, first check all the upstream
(RS232) connections from the first Comms module (type F) to the PC.
The downstream (RS485) connections do not affect the On Line / Off
Line message.
Refer to the connection diagrams in the chapter on the Comms
module and check each one carefully. Points to check are:
•
Check that the RS232 cable is connected to CONN2 on the
Comms module (upstream - direction A - RS232) and not to
CONN1, CONN3 or CONN4.
•
CTS and RTS must be linked at the Comms module. If the
upstream TX LED (the left hand LED of the left hand pair) is
on continuously this shows CTS and RTS are not linked.
•
Check that the upstream (direction A) jumpers (JU1 and JU2)
on the Comms module are set to 9600 baud, RS232. (If you