SI-B Communication Error

What does BUS mean?

This fault occurs when using the SI-B or CP-916 communication options if communication is lost after being established. It signifies a disruption in communication with the option card, which can halt control functions or data exchange, leading to operational stoppage and loss of control.

• Loose or damaged communication cable (e.g., Cat5e, RS-485) between the inverter and the SI-B/CP-916 card or master device.
• Incorrect termination resistor setting on the SI-B/CP-916 card or the communication bus line.
• Electromagnetic interference (EMI) disrupting the communication signal due to improper cable shielding or grounding.
• Faulty SI-B or CP-916 communication option card requiring replacement.
• Incorrect communication parameters (e.g., baud rate, parity, data bits, station address) configured in P5-XX range (for SI-B) or CP-916 card settings.

Click steps to track your progress.

1. 1

   Verify physical connections of the communication cable (e.g., terminals TB1/TB2 for RS-485) at both the inverter SI-B/CP-916 card and the master device.

2. 2

   Measure the communication cable continuity and insulation resistance using a multimeter to detect breaks or shorts.

3. 3

   Confirm correct termination resistor switch (SW1) setting on the SI-B/CP-916 card (ON for end devices, OFF for middle devices).

4. 4

   Check communication parameters (e.g., P5-01, P5-02, P5-03 for SI-B) in the inverter and the master device for matching values.

5. 5

   Inspect the SI-B/CP-916 option card for visible damage and test with a known good card if available.