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Omron Error Code Reference

Omron PLC & Servo error code reference with causes and solutions

55 results

About Omron Error Code Reference

The Omron Error Code Reference provides a comprehensive, searchable database of Omron PLC, servo drive, and communication system error codes. It covers CJ/NJ/NX series PLC fatal errors (0x00D0, 0x00C0, 0x0400, 0x009B, 0x0081) and non-fatal errors (0x00B0, 0x00E1, 0x0200, 0x009A, 0x8000), CPU and memory errors (WDT Err 23, DM/EM range errors, I/O point overflow), and EtherCAT master/slave communication faults with detailed root cause analysis.

Additionally, this reference includes Omron G5 servo drive alarms such as A.020 (parameter error), A.040 (overcurrent), A.100 (overspeed), A.400 (overload), A.510 (overvoltage), A.710 (undervoltage), A.810 (encoder error), A.900 (encoder battery), A.CF0 (EEPROM error), and A.F10 (overheat). Motion control errors covering following error, soft/hard limits, homing, cam table, and axis synchronization are also documented alongside I/O module diagnostics for analog, thermocouple, counter, and serial communication units.

Each error code includes numbered resolution steps, making it an essential field reference for automation engineers and maintenance technicians. All processing happens locally in your browser with dark mode support.

Key Features

  • Searchable Omron CJ/NJ/NX PLC fatal and non-fatal error codes with root cause analysis and numbered resolution steps
  • G5 servo drive alarm reference: A.020, A.040, A.100, A.400, A.510, A.710, A.810, A.900, A.CF0, A.F10
  • EtherCAT communication fault codes: master initialization, slave disconnection, CRC errors, topology, WKC, DC sync, PDO mapping
  • CPU and memory error diagnostics: WDT timeout, DM/EM range overflow, I/O point overflow, SD card, EtherNet/IP, duplex errors
  • Motion control error reference: following error (0x3060), soft/hard limits, homing, overspeed, cam table, axis sync, command collision
  • I/O module diagnostics: analog input/output, thermocouple/RTD, high-speed counter, serial communication, position control units
  • Detailed cause-and-solution format with 4-5 potential causes and 5 numbered resolution steps per error code
  • Organized by category (PLC System, CPU & Memory, EtherCAT, Servo Drive, Motion Control, I/O Module) for fast field lookup

Frequently Asked Questions

What does Omron PLC Fatal Error 0x00D0 mean?

Fatal Error 0x00D0 indicates an I/O bus error on the Omron CJ/NJ series PLC backplane. The CPU cannot communicate with one or more I/O units. Check that all units are firmly seated, verify the end cover is on the last unit, inspect backplane connector pins for damage, remove units one by one to isolate the fault, and power cycle the PLC after reseating units.

How do I clear Omron G5 servo alarm A.020 (parameter error)?

Alarm A.020 indicates a servo parameter is outside its valid range or parameters conflict with each other. Connect via CX-Drive or Sysmac Studio to identify the offending parameter, correct it to within the documented range, and reset the alarm by toggling the alarm reset input (CN1 pin 1) or cycling power. If the issue persists, restore factory defaults with Fn005 and reconfigure.

How do I diagnose EtherCAT CRC frame errors on Omron NJ/NX?

EtherCAT Frame Error 0x0010 indicates CRC mismatches caused by cable quality issues, electromagnetic interference, or connector problems. Replace cables with industrial-grade Cat5e STP or better, ensure adequate separation from high-voltage power lines, reseat connectors, monitor CRC error counters in Sysmac Studio, and verify shield grounding on both ends.

What causes Omron WDT (Watchdog Timer) error Err 23?

Err 23 means the task execution time exceeded the configured watchdog period. This is typically caused by infinite loops, excessive FOR-NEXT iterations, large data table processing, or overloaded interrupt tasks. Optimize program logic, distribute processing across multiple cycles, use Sysmac Studio task monitoring to find bottlenecks, and consider splitting into multiple tasks.

How do I resolve Omron servo alarm A.810 (encoder error)?

A.810 indicates serial communication failure between the encoder and servo amplifier. Check encoder cable (CN2) connections, verify cable length is within 20m, confirm shield grounding (single-point at amplifier side), measure encoder power voltage (5V DC), and if the encoder is built-in, replace the motor. Intermittent errors often point to loose connectors or damaged cable shielding.

What does Motion Error 0x3060 (following error) mean?

Following error 0x3060 occurs when the deviation between the commanded position and actual position exceeds the tolerance (Pn520). Causes include insufficient servo gain, sudden mechanical load changes, collisions, or encoder feedback issues. Disable the axis with MC_Power, inspect the mechanism, retune servo gains, check for mechanical friction, and reduce move speed/acceleration if needed.

How do I fix Omron Non-fatal Error 0x00B0 (I/O table mismatch)?

Error 0x00B0 means the registered I/O table does not match the physically mounted units. This happens after adding, removing, or replacing units. Compare the I/O table in CX-Programmer with actual hardware, regenerate the table (PLC > I/O Table > Create), verify DIP switch settings on units, transfer the updated table, and power cycle. Watch for CJ1/CJ2 series compatibility differences.

Is this Omron error code reference free?

Yes, this reference is completely free with no usage limits, no account required, and no software installation needed. It covers 55+ Omron error codes across PLC, servo, EtherCAT, motion control, and I/O modules. All data is processed locally in your browser. It is part of liminfo.com's free online engineering tool collection.