PS0111

Press ALARM button to display full alarm message and note the O-number and N-block where PS0111 was triggered. Record the exact sequence number for reference.

Navigate to EDIT mode and review the macro program at the reported block. Identify all macro variable calculations (#i=#j*#k or #i=#j+#k operations) in that block and surrounding lines.

Go to SYSTEM > MACRO > display current macro variable values. Check common variables #100-#199 and #500-#999 used in the calculation. Verify none exceed +/-99999999 or are generating exponential growth through loop iterations.

Modify the macro program to add range checking (IF[#i GT 9999999]THEN GOTO...) or insert intermediate calculations to break down operations into smaller magnitude steps. Re-test with controlled input values.

Access the macro program in EDIT mode and locate the block number from the alarm message. Look for division operations (#i=#j/#k), SQRT, SIN, COS, TAN, ATAN functions in the calculation line.

Navigate to SYSTEM > MACRO and check the current values of all macro variables involved in the flagged calculation. Specifically verify divisor variables are non-zero and SQRT arguments are positive.

Insert conditional checks before problematic operations: IF[#k EQ 0]THEN #k=0.001 (for division) or IF[#i LT 0]THEN #i=ABS[#i] (for SQRT). Add error handling routines using GOTO statements to trap invalid conditions.

Ensure error handling does not mask legitimate calculation errors that indicate upstream logic problems in the macro program.

Verify parameter 6001 bit 4 (ABS/INC modal) and parameter 6006 (macro variable range checking) are set correctly. Default settings should catch these errors, but verify custom parameter modifications have not disabled protection.

In SYSTEM > MACRO display, identify all macro variables used in the alarm block. Null or uninitialized variables show as empty/blank. Note which variables lack assigned values.

Review macro program initialization section (typically at program start after O-number). Verify all variables used in calculations are explicitly initialized: #100=0, #101=1, etc. Check for conditional branches that might skip initialization.

Add null-checking logic before calculations: IF[#i EQ #0]THEN #i=0 (where #0 represents null). This prevents operations on uninitialized variables and provides default safe values.

Check parameter 6008 (macro variable initialization setting). Verify it matches application requirements. Review program logic for variables assigned via external input (G65 P-Q arguments) that may not always be passed, leaving variables null.