ABB AC500 CPUs

This is a fatal error indicating that the safe function of the operating system is no longer guaranteed. It typically arises from critical issues such as a checksum error in the system Flash memory or a RAM error, compromising the CPU's core operations. This error demands immediate attention as the system will not operate reliably, potentially leading to unpredictable behavior or complete system failure.

This severe error signifies that while the operating system itself is functioning, the error-free processing of the user program cannot be guaranteed. A common cause is a checksum error detected in the user Flash memory, which impacts program execution stability. Unresolved, this can lead to incorrect program logic, unexpected machine behavior, or intermittent operational failures without crashing the entire OS.

A light error indicates a problem that may or may not require the user program to be stopped, depending on the application's design. Examples include issues where Flash memory could not be programmed or an I/O module has failed, but the CPU itself remains operational. The user must decide the appropriate reaction, as ignoring it might lead to impaired functionality of specific I/O or program segments without halting the entire system.

This warning indicates an error in the periphery, such as an I/O module, which might only have future implications rather than immediate system failure. Specific examples include a short-circuit detected at an I/O module or an exhausted/missing battery. The user is responsible for deciding the necessary reaction, as ignoring it could lead to data loss (e.g., due to battery failure) or damage to peripheral components over time.