14757

Common Causes

• Incorrect WHENEVER, FROM, or DO clause used with H or M function outputs in motion synchronous action
• RET command programmed outside of technology cycle context
• MEASA, MEAWA, or MEAC function paired with incompatible conditional clauses (WHENEVER, FROM)
• Multiple feed rates specified within a technology cycle where only single feed is allowed
• Conflicting synchronous action syntax combining restricted function types

Troubleshooting Steps

1. 1Review the NC program at channel %1, block %2 and identify the motion synchronous action statement causing the alarm
2. 2Verify RET commands are only used within technology cycle blocks; move RET outside technology cycles if present
3. 3Check H and M function outputs - remove WHENEVER, FROM, and DO clauses and use alternative synchronization methods
4. 4Inspect MEASA, MEAWA, and MEAC functions - replace WHENEVER and FROM conditions with allowed alternatives such as EVERY or direct block synchronization
5. 5Confirm 'Several feeds' function is not active within technology cycle; restructure program to apply multiple feeds outside technology cycle scope
6. 6Consult Siemens 840D/828D programming manual section on motion synchronous actions and allowed function/clause combinations
7. 7Correct the NC syntax and reload the program; monitor for alarm recurrence