Pro-face RHAA073: Illegal write request because this device has been off scan

Pro-face HMI Major Communication

Model: GP4000/SP5000 Series | Code: RHAA073

Applicable Systems
GP4000 Series

Symptoms

  • GP-Pro EX display unit shows error RHAA073: Illegal write request because this device has been off scan.

Possible Causes

  • A write request was made (switch, D-script, Pro-Server EX) to a device whose communication scan has been stopped.

Troubleshooting Steps

  1. Step 1: Turn OFF the appropriate bit between LS9550 and LS9559 to restart communication scan of the connected device.
    Communication restored and error cleared

How to Reset

Repower or reset the display unit after correcting the root cause.

Related Pro-face Fault Codes

Source: Pro-face GP-Pro EX Maintenance/Troubleshooting Manual, T.7.1 Common Display errors (proface.tech/otasuke official)

Category: HMI