Communication Timeout Fault
Yaskawa · F7 Drive
What does CE mean?
This fault indicates a loss of serial communication (e.g., Modbus) between the drive and its control system for more than 2 seconds, affecting parameters like H5-04 and H5-05. The drive will execute a programmed stopping method, becoming unresponsive to external commands. Prolonged communication loss can lead to process interruption and potential safety hazards if the drive is not properly controlled.
Common Causes
- Loss of communication from the master controller (e.g., PLC, HMI) to the drive, due to a program stop, power loss, or communication port failure on the master.
- Intermittent or broken network cable connection between the drive and the master, causing data packets to be lost or corrupted.
- Incorrectly configured communication timeout settings (e.g., H5-04 Communication Timeout Detection Time, H5-05 Communication Timeout Action) in the drive.
- Excessive network traffic, latency, or bus contention preventing the drive from receiving a valid command within the timeout period.
- Incorrect network address (H5-02) for the drive, causing the master to send commands to the wrong device or the drive to ignore incoming messages.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Verify the operational status of the master controller (PLC/HMI) and its communication port, ensuring it is powered on and actively sending commands to the drive.
- 2
Inspect the network cable and connectors between the drive and the master for physical damage, looseness, or intermittence, using a cable tester if available.
- 3
Adjust parameter H5-04 (Communication Timeout Detection Time) to a longer duration (e.g., 5-10 seconds) to account for expected network latency or intermittent traffic.
- 4
Confirm that parameter H5-02 (Communication Node Address) on the drive matches the address configured in the master controller's communication settings.
- 5
Use network diagnostic tools to monitor the serial communication bus (e.g., Modbus RTU traffic) for errors, delays, or periods of inactivity from the master.