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CAN Communication ports testing ports testing
Introduction
Solis inverters use CAN (Controller Area Network) communication primarily for connecting hybrid inverters with compatible battery systems and facilitating inverter-to-inverter communication in parallel setups. Despite its robust nature, CAN communication can occasionally encounter issues. This article focuses exclusively on CAN troubleshooting methods for Solis inverters, helping you identify and resolve common communication errors effectively.
Understanding CAN Communication in Solis Inverters
CAN (Controller Area Network):
Primarily used for communication between hybrid inverters and compatible battery systems, as well as for inverter-to-inverter communication in parallel or off-grid setups. CAN provides high-speed, reliable data exchange essential for synchronization and battery management.
Common Communication Issues and Their Causes
CAN Issues:
- Battery not recognized by inverter
- Frequent communication loss between inverter and battery
- Incorrect battery status readings
- Inverters in parallel mode not syncing
General Troubleshooting steps
✅ 1. Visual Inspection
- Ensure that the connector is properly inserted and secured.
- Check for any physical damage to the connector or cable.
- Look for burn marks or corrosion on the port.
✅ 2. Interference and Grounding
- Shielded Cables: Use shielded twisted-pair cables to minimize electromagnetic interference.
- Proper Grounding: Ensure all devices share a common ground reference to prevent ground loops.
✅ 3. Cable and Connection Testing
- Use a LAN cable tester or multimeter to verify continuity from one end of the cable to the other.
- Ensure the correct wiring between devices (miswiring can prevent communication).
✅ 4. Firmware and Software Checks
- Firmware Updates: Verify that the inverter and connected devices have the latest firmware versions.
✅ 5. Swap Devices
- Test the inverter with a known-working CAN device.
- Alternatively, test the external device with another known-working inverter.
CAN Troubleshooting
CAN Port – RHI 5G Series and S6 Series
The PIN Assignment for the CAN Port is as follows:
✅ 1: Voltage Level Check
• Measure the voltage on CAN H and CAN L:
o CAN H to GND: 2.5V to 3.3V (active state).
o CAN L to GND: 1.5V to 2.5V (active state).
o If no voltage is present, the bus may be disconnected or faulty.
✅ 2: Communication Testing
• Connect a USB-to-CAN adapter and check for signal transmission using PC software like CANalyzer, PCAN-View, or a similar tool.
• Use an oscilloscope to check CAN signals:
o A working CAN bus should show square wave signals on CAN H and CAN L.
✅ 3: Known Issues and Distance Limitations
• CAN Between Parallel Inverters:
o When inverters are paralleled and connected via CAN, "Mode Conflict" alarms may occur if the connected inverters have different battery capacities. Ensure all inverters in the system are configured identically.
(Exception: S6-EH3P(29.9-50)K-H)
o Too long a CAN cable run between inverters can also trigger communication errors, especially in older firmware versions. Keeping cable runs short and updating to the latest firmware can help mitigate this issue.
