4. Troubleshooting (DeviceNet)
4.1.2.3 Master: Unestablished Communication
Master Unit LED
MS NS Error Description
Green
Light ON
Light
OFF
Master
Unestablished
communication
Communications power supply OFF
No slave
♦ Process Flowchart
6
No Problem
Check
Check the following:
- Unconnected terminating resistor
- Unconnected or loose connector/signal wire
- Cable disconnection
Finish
Measure voltage of
communications power supply
at the master unit.
No Problem
No Problem
No Problem
Problem exists. (Fix it.)
Problem exists. (Fix it.)
Check that power is supplied to all slaves.
Replace the master unit.
Problem exists. (Fix it.)
Problem exists. (Fix it.)
No problem
No problem
No problem
No problem
Check for master unit configuration.
See 4.1.3.1 and 4.1.3.2.
Fieldbus I/O Rev.6 89