Issue:
The Red LED labeled ERR is blinking/flashing on M241 series PLC. What does it mean?
Product Line
The LED turns on for 500ms and then off for 500ms regularly.
This signifies an INVALID_OS controller state There is not a valid firmware file present in the flash memory. The controller does not execute the application. Refer to the Firmware Upgrade section of the SoMachine HTML Help to restore a correct state.
Single flash -
The LED turns on for 1000ms, then off for a short 200ms and repeats this pattern.
This signifies an EMPTY controller state, no program has been loaded to the PLC in this state (usually after a Firmware Upgrade procedure has been done or when a Reset Origin is performed)
Fast flash -
The LED flashes on and off alternating quickly within 500ms at a regular pace.
This signifies an EMPTY after a system error detected controller state.
This state is the same as the normal EMPTY state. But the application is present (as a BOOT project), and is intentionally not loaded into working memory. A next reboot (power cycle), or a new application download, will restore correct state.
For more information, please refer to the SoMachine HTML Help in the section:
Logic Controllers -> M241 Logic Controller -> Programming Guide -> Controller States and Behaviors -> Controller States Description
