Sensaphone SCADA 3000 Users manual - Manual (Page 297)

H-5
Appendix H: Troubleshooting
• The communications bus is not properly wired. The communications bus wiring requires a
4-conductor cable. Two conductors are used for the A&B pair and the other two are used for
the Y&Z pair. Make sure the wiring is reversed between the expansion modules and the main
unit, but remains straight through between the modules. See Chapter 7 (I/O Expansion Modules)
for more information on communications Bus Termination.
• There is an Expansion Module bus address conflict. Up to 15 I/O expansion modules may
be connected to the SCADA 3000 main unit to provide additional inputs and/or outputs. Each
module must be configured with its own unique address using the BUS ADDRESS jumpers.
See the chapter for the specific I/O expansion module for information on setting BUS addresses.
• There may be a loose or open connection in the communications bus wiring. All 4 wires
must be connected to an expansion module for the SCADA 3000 main unit to communicate
with it. Check for an open bus connection by using a DC voltmeter and checking the voltage
between the Y and Z terminals on the SCADA 3000 MAIN UNIT. If all the bus connections
are complete, you will see about 2.4 Volts DC. If you see 4.5 Volts DC, there is an open bus
connection somewhere.
Why won’t my Ladder-Logic program run?
The CTRL switch on the SCADA 3000 unit is in the Disable position.
Why won’t my C program run?
The CTRL switch on the SCADA 3000 unit is in the Disable position.
Universal Input module
I have power wired to the Universal Input module but the green LeD is off.
You probably have a blown fuse. Check your wiring and replace the fuse.
The green LeD is on but the yellow LeD is off.
This means that the module and main unit are not communicating. It could be a problem with
either device. Check the wiring first. Make sure the main unit is on and functioning. Try
powering-up both devices.
my input readings are not correct.
Make sure the configuration jumper for the input is in the correct position. Make sure the
software is configured correctly for your type of sensor.
Pulse Count module
If the pulse count total overflows, does that cause the rate calculation to be incor-
rect?
No. The rate is computed independent of the pulse total.
I have power wired to the Pulse Count module but no lights are on.
You probably have a blown fuse.