Q4 CONTROLLER II Operation and Maintenance Manual
Q4 Controller II Operation Manual
- 24 -
Dec 02, 2021
85350-101-000 Rev A
9. Troubleshooting
Q4 Controller has advanced features and functions. Before assuming that unexpected behavior is
caused by a system defect or breakdown, the operator should use this manual to become
thoroughly familiar with the controller operation. This troubleshooting guide is intended as an aid
in identifying the cause of unexpected behavior and determining whether the behavior is due to
normal operation or an internal or external problem.
Identify the symptom or unexpected behavior you are observing from the symptoms listed in the
table. A probable cause is provided, and a suggested solution is proposed including references to
manual sections that provide information that may be of assistance.
SYMPTOMS
PROBABLE CAUSE
SUGGESTED SOLUTION
LCD Display does not come on
No power supply
LCD has problem
Program has crashed
Check power / ground connections
Change LCD
Reprogram
M-View reports “Q4 Controller is
offline”
Q4 Controller is not
turned on
USB is not recognized
by PC computer
Turn on Q4 Controller
Unplug the USB cable and plug again
Check Q4 Controller is connected properly.
Be sure that the port on the computer is
active.
Q4 Controller reports “Vote no
Sensor!” or “AV no Sensor!”
No sensor was assigned
to the output (relay,
buzzer, or strobe)
Assign sensor to the output
Q4 Controller reports “Sensor
Offline”
Comm setting is wrong
Connection is wrong
Remote Device is in
Fault
End-of-line matching
resistors are not
properly set.
Check the remote baud rate in Q4
Controller System Setting is same as the
baud rate in Digital Sensor, 4800bps is
default.
Check connection between Q4 Controller
and Digital Sensor. Make sure all have
power on and no shorts or opens in wiring.
Be certain that polarity for RS-485
connections is correct. A-A and B-B
Examine remote devices
Review end-of-line resistor settings
