CPU LED Display

An LED display is located on the front panel of the CPU:

NOTE: The SEC LED, indicating secure communication status, is not implemented for this version release.
NOTE: The Copro LED display is a sub-set of the CPU display, and includes the following LEDs:

  • ERR

  • DL

  • SRUN

  • SMOD

LED Descriptions

NOTE: Refer to the topics:

LED Indicator

Applies to...

Description

CPU

Copro

RUN

✔

–

ON: The CPU is managing its outputs, and at least one task is in the RUN state.

ERR

✔

✔

ON: The CPU has detected an internal CPU error (for example, no configuration, detected watchdog error, detected self test error.)

I/O

✔

–

ON: The CPU has detected an error, external to the CPU, in one or more I/O modules.

DL (download)

✔

+

  • ON: A firmware upgrade to the CPU, Copro, backplane or other in-rack module is in progress.

  • OFF: No firmware upgrade in progress.

BACKUP

✔

–

ON:

  • The memory card or CPU flash memory is missing or inoperable.

  • The memory card is not usable (bad format, unrecognized type).

  • The memory card or CPU flash memory content is inconsistent with the current application.

  • The memory card has been removed and reinserted.

  • A PLC > Project Backup... > Backup Clear command has been performed when no memory card is present. The BACKUP LED remains ON until the project is successfully backed up.

OFF: The memory card or CPU flash memory content is valid, and the application in the execution memory is identical.

ETH MS

✔

–

MOD STATUS (green/red): Pattern indicates the Ethernet port configuration status.

NOTE: With the detection of a recoverable error, the ETH MS LED can be green or red and on or off.

ETH NS

✔

–

NET STATUS (green/red): Pattern indicates the Ethernet connection status.

FORCED I/O

✔

–

ON: At least one input or output on a digital I/O module is forced.

SRUN

✔

✔

ON: The PAC is managing its safety outputs, and the SAFE task is in the RUN state.

SMOD

✔

✔

✔: Applies

– : Does not apply.