12
Hardware Problems
This section deals primarily with troubleshooting problems with the PLC discrete inputs. At the end of this
section is the all important “missing heads” section.
Problem Topic
Explanation/Solution
“Hub is initializing” Is the hub
locked up?
This message remains until the
hub has sent the OK to software
indicating all of its heads have
arrived at operating temperature.
No problem, just wait until all
heads have warmed up.
Terminal screws not tightened
firmly on wires
Terminal not plugged in properly
Loose or broken power wires
Improper power connection.
Contamination has entered the
terminal and is preventing a
reliable connection
Over-current situation caused by
a short or overload. Re-settable
fuse opens.
Fix the short or overload
problem, wait a little bit and re-
apply power.
Over-voltage situation (exceeds
30VDC or 26V AC). Re-settable
fuse opens.
Voltage spec is 24V +/- 2V.
Correct voltage supplied to hub
and then re-apply power.
Hub won’t power up, hub loses
power, or keeps cycling on and
off.
Power supply does not provide
enough current at power-up.
Make sure power supply can
provide at least 2.5A at start up.
Hub has not been reset after
heads have been
connected/disconnected. Reset
hub and try again.
“Read” input does not work,
system does not measure.
“Read” LED indicator lights up
properly when both “Read”
button and “Read” Input are used.
“Read” LED Indicator light does
not work with input.
Hub may have just powered up
and is still trying to initialize. (see
flashing “
01
” state under hub
operation. Wait until the hub
indicates a solid “
01
” before
attempting to measure.
