Troubleshooting
372 SPU 780 01EMAN May 2002 275
Procedure Two To replace a P930/P933 fuse:
Procedure Three Failure to attach to a running controller:
Procedure Four If Modbus Plus is the chosen mode of communication, please ensure that the
Modbus Plus driver software is installed. You may use the Modbus Plus diagno sti c
tools included with the driver suite. Check if the Modbus Plus act ive L ED is flas hing
both at the interface card (PCI85 or SA85) and at the PLC. Normal indication is six
times per second.
Step Action
1 Turn off the P930/P933 power supply.
2 Turn off the supply power to the power supply.
3 Remove the supply power line from the P930/P933 power terminal.
4 Loosen mounting screws on top and bottom of the front face of the P930/P933
and slide the P930/P933 out of the chassis.
5 Replace fuse with on of the same type and size.
Step Action
1 Ensure that the proper cables and software are being used.
2 Are the communication parameters on the computer the same as those on the
controller?
3 Check the cable attachment and pinout.
4 If Modbus Plus is being used then ensure the Modbus Plus driver is installed and
the Modbus Plus active LED on the SA85 or PC85 card and the controller are
flashing at six times a second. (The Modbus Plus Indicator normal operating
state.)
5 If this is the first time this cable has been used then test the cable.