12589

Common Causes

• Modal ID in motion synchronous action defined directly using an online variable instead of intermediate register
• Attempting to use $AC_MARKER array element directly in ID parameter without assignment to local variable first
• Using input variable ($a_in) or other online variables directly in motion synchronous ID definition
• Incorrect syntax in WHEN/DO clause referencing online variables for modal identification
• Program structure attempting dynamic ID assignment that violates motion synchronous action constraints

Troubleshooting Steps

1. 1Locate the motion synchronous action block in channel %1 at block %2 and identify the variable %3 being used in the ID parameter
2. 2Review the syntax: if ID parameter directly references online variables like $AC_MARKER[], $a_in[], or similar, this is the root cause
3. 3Replace direct online variable reference with intermediate register assignment - assign the online variable value to a local register (R-parameter) before the synchronous action block
4. 4Update the ID parameter to reference the intermediate register instead of the online variable, maintaining the WHEN/DO clause logic unchanged
5. 5Verify corrected syntax matches the pattern: R-register assignment, then ID=R-register reference, followed by WHEN/DO conditions