Pro-face GP-Pro EX — Communication Error (RHAA065/066)

Pro-face · intermediate · 25 min

A Pro-face GP4000 showing RHAA065/RHAA066 has an Ethernet communication problem to the PLC. Ping both ends, then verify the Device/PLC settings in offline mode against the connection manual.

ℹ️ Pro-face error codes are specific: RHAA065/RHAA066 point straight at Ethernet communication. Use ping to prove the physical path, then fix the driver settings.

What the error tells you

On a Pro-face GP4000 / GP-Pro EX display, communication error messages appear across all drivers (device/PLC types) when the panel can't talk to the connected controller. When the codes shown are RHAA065 and RHAA066, there is specifically a problem with Ethernet communication — that narrows the search to the network path and the Ethernet driver settings.

Prove the physical path with ping

1. If your PC is on the same network, ping the GP and ping the connected device: ping <IP address> for each.
2. If the device replies but the GP doesn't (or vice versa), you have a network/addressing problem — wrong IP, wrong subnet, a cabling/switch fault, or the device is off.
3. If both reply to ping but the panel still shows RHAA065/066, the physical path is fine and the problem is in the driver / protocol configuration.

Check the Device/PLC settings

1. Put the display unit into offline mode.
2. Go to Peripheral Settings → Device/PLC Settings.
3. Verify the communication settings against the GP-Pro EX Device/PLC Connection Manual for your specific PLC driver: IP address, port, protocol, unit/node address, and any driver-specific parameters. A mismatch here is the usual cause when ping succeeds but comms fail.

Step-by-step

1. Read the exact code on the panel — RHAA065/RHAA066 confirms Ethernet.
2. Ping both ends to isolate physical/network vs. configuration.
3. Physical/network: fix IP/subnet, cabling, switch, or a powered-off device if ping fails.
4. Configuration: in offline mode, correct the Device/PLC driver settings per the Connection Manual if ping succeeds but comms don't.
5. Re-transfer the project if you changed the driver configuration in GP-Pro EX, then confirm comms come up.

Verify

Once corrected, the RHAA errors clear and tags update live. If RHAA065/066 returns after both ends ping cleanly, re-check the driver's node/unit address and protocol parameters — those are the settings a successful ping doesn't validate.