Pro-face RHAA093: COM1 Cannot join Multilink token; request unreceivable

Pro-face HMI Critical Communication

Model: GP4000/SP5000 Series | Code: RHAA093

Applicable Systems
GP4000 Series

Symptoms

  • GP-Pro EX display unit shows error RHAA093: COM1 Cannot join Multilink token; request unreceivable.

Possible Causes

  • Communication has failed for 2 hours; write and read requests could not be processed.

Troubleshooting Steps

  1. Step 1: Add the display unit to the list of Multilink stations; check if any unit is monopolizing the PLC for more than 2 hours.
    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