Yaskawa BACnet MS/TP - Manual (Page 25)

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. For additional error codes that may appear on the drive digital
operator, refer to the drive Technical Manual.
n Faults
Both bUS (SI-B3 option communication error) and EF0 (External fault input from the SI-B3
option) 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 frequency reference is assigned to an
option card.
Cause Possible Solution
No signal was received from the
PLC
• Check for faulty wiring.
• Correct the wiring.
• Check for disconnected cables and short circuits and repair as needed.
Faulty communications wiring or
an existing short circuit
Communication data error
occurred due to electrical
inteference
• Check the various options available to minimize the effects of noise.
• Counteract noise in the control circuit, main circuit, and ground wiring.
• Ensure that other equipment such as switches or relays do not cause electrical
inteference. Use surge absorbers if necessary.
• Use only recommended cables or other shielded line. Ground the shield on the
controller side or the drive input power side.
• Separate all communication wiring from drive power lines. Install an EMC
noise filter to the drive power supply input.
The option card is damaged
Replace the option card if there are no problems with the wiring and the error
continues to occur.
7 Troubleshooting
YASKAWA TOEP YEACOM 08A A1000 Option BACnet MS/TP SI-B3 Installation & Technical Manual 25