Yaskawa BACnet MS/TP SI-B3/V - Manual (Page 31)

7 Troubleshooting
u Drive-Side Error Codes
Drive-side error codes appear on the drive digital operator. Causes of the errors and corrective
actions are listed below. Refer to the drive manual for additional error codes that may appear
on the drive digital operator.
n Faults
Both bUS (Option Communication Error) and EF0 (Option Card External Fault) can appear
as an alarm or as a fault. When a fault occurs, the digital operator ALM LED remains lit.
When an alarm occurs, the ALM LED flashes.
If communication stops while the drive is running, use the following questions as a guide to
help remedy the fault:
• Is the option properly installed?
• Are the communication lines properly connected to the option? Are the wires loose?
• Is the controller program working? Has the controller/PLC CPU stopped?
• Did a momentary power loss interrupt communications?
Digital Operator Display Fault Name
bUS
Option Communication Error
• The connection was lost after establishing initial communication.
• Only detected when the Run command or frequency reference is assigned to
the option (b1-01 = 3 or b1-02 = 3).
Cause Possible Solution
Master controller (PLC) has
stopped communicating
• Check that power is supplied to the PLC
• Check that PLC is not in program mode
Communication cable is not
connected properly
• Check for faulty wiring
• Correct any wiring problems
A data error occurred due to noise
• Check the various options available to minimize the effects of noise
• Counteract noise in the control circuit, main circuit, and ground wiring
• If a magnetic contactor is identified as a source of noise, install a surge absorber
to the contactor coil
• Make sure the cable used meets requirements
• Make sure the option ground wire is connected between option FE terminal
and the drive ground terminal connected to earth ground
• If available, use IG5 to connect to network common. Refer to Connection
Diagram for Multiple Connections on page 26 for proper wiring.
Option is damaged
If there are no problems with the wiring and the error continues to occur, replace
the option.
7 Troubleshooting
YASKAWA TOEP YAICOM 19A V1000 Option BACnet MS/TP SI-B3/V Installation & Technical Manual 31