Troubleshooting
CoolMaster User Manual
20
www.coolautomation.com
© 2008 Cool Automation
Troubleshooting
6
Symptom
Cause
What to do
1
The LCD of the
CoolMaster is off
(there is no visible
display on it).
a. Incorrect power supply
a. Check the power adaptor and supplied
voltage. Must be stable 9v DC.
2
After connecting the
CoolMaster it does
not show on its LCD
the correct number of
indoor units.
a. It takes several minutes
to recognize the system.
b. The communication line
to the air conditioner is
connected improperly.
a. Wait for about 5 minutes
b. Check the connection of the air conditioner
communication line. Look if the upper led is
blinking.
c. If the led is off, check the wiring connection
of the communication line.
3
The communication
does not work (the
system does not react
to any of your sent
commands).
a. Improper serial port
definitions.
b. The centralized
addresses of the indoor
units are not defined.
c. The wires: transmit and
receive of the RS232 cable
are not twisted.
d. Carriage return has not
been added to your
command.
a. Check that all port definitions (baud rate,
flow control, parity etc’) are properly defined.
b. Define the centralized addresses of all
indoor units.
c. Check and fix the RS232 cable connection
(twisting the Tx and Rx wires).
d. Add “0d” at the end of the command that is
sent to the CoolMaster.
4
The typed commands
cannot be seen on the
"hyper terminal"
screen
a. The echo is set to "off".
a. Run "echo" command and set "echo" to
"On".