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ErrorLib — Industrial Fault Code Library

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12359

Read request is nested

Fanuc · R-30iA R-30iB Controller

What does 12359 mean?

A read request was initiated while another read request was already active for the same resource or file_id. This IO_STATUS error indicates an attempt to perform concurrent read operations which is not supported or allowed for the specific resource. The program will abort if the file_id is invalid.

Common Causes

  • Program logic error attempting multiple reads on the same file_id concurrently without proper synchronization or completion checks.
  • Failure to properly complete or close a previous read request before initiating a new one.
  • The file_id used does not correspond to a valid opened file, leading to confusion in state management.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Review KAREL program logic to ensure read requests are handled sequentially for a given file_id and resource.

  2. 2

    Verify that previous read operations are fully completed and their results processed before initiating new ones on the same resource.

  3. 3

    Use the KAREL command READ file_id(cr) to clear any existing IO_STATUS error condition.

Browse all codes in this manual (31)
Verified technical data. Last updated: April 2026

Related Faults

12328File is not opened12329Cannot write the variable12330Write file failed
Source: Fanuc R-30iA R-30iB Controller
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