Motion Fault and Alarm Exceptions

There are two exceptions:

These two attributes are a bitmapped collection of the fault and alarm exception conditions associated with the motion planner function. When one of the listed excepted conditions is detected by the controller, the condition is indicated as a Fault or Alarm according to the associated Motion Exception Action attribute value. In general, Alarms are considered warnings by the control system while Faults result in some form of action to stop the axis.

This table defines the current list of motion exception conditions from which the Motion Fault and Motion Alarm bits are derived:

Soft Travel Limit - Positive

This exception condition occurs when Soft Travel Checking is enabled and when actual position has exceeded the configured Soft Travel Limit - Positive attribute value in  the positive direction.

If the Motion Exception Action for this bit is set for Stop Planner, the faulted axis can be moved or jogged back inside the soft travel limits. Any attempt, however, to move the axis further beyond the Soft Travel Limit - Positive value using a motion instruction will result in an instruction error.

Soft Travel Limit - Negative

This exception condition occurs when Soft Travel Checking is enabled and when actual position has exceeded the configured Soft Travel Limit - Negative attribute value in the negative direction.

If the Motion Exception Action for this bit is set for Stop Planner, the faulted axis can be moved or jogged back inside the soft travel limits. Any attempt, however, to move the axis further beyond the Soft Travel Limit - Negative value using a motion instruction will result in an instruction error.

As soon as the axis is moved back within the specified soft travel limits, the corresponding Soft Travel Limit - Negative fault bit needs to be reset. The soft travel fault will persist through any attempt to clear it while the axis position is still beyond the Soft Travel Limit - Negative value with the axis enabled.