Wear Monitoring; Tool Life Monitoring; Workpiece Count - Siemens SINUMERIK 840 Planning Manual

2 Description of Functions 11.92

2.2.3 Wear monitoring

2.2.3 Wear monitoring
Tool management supports two types of wear monitoring, monitoring of tool life and monitoring
of number of pieces.

2.2.3.1 Tool life monitoring

The user defines a maximum processing period when loading the tool. In addition, it is possible
to implement a prewarning limit. Both times must be stored in consecutive P memories. The
monitoring function is carried out by function block FB 156 "Tool life monitoring/prewarning
limit".
If the tool is not to be processed, "9999" has to be entered: in this way, tool life monitoring is
deactivated for this tool.
Tool life is being decremented as long as the "BEAR" parameter has a "high" signal. If a
prewarning limit is programmed, bit 0 is set in DB 152 "Prewarning limit reached" as soon as
the actual values fall short of the prewarning limit. If the tool life expires during machining, bit
10 "Tool disabled" or bit 6 "Disable tool at program end" is set depending on the parameter
assignment of FB 156.
If the tool is disabled immediately, it is no longer available for further machining as soon as it is
returned to the magazine; however, the current machining process will be completed.

2.2.3.2 Workpiece count

The user specifies a maximum number of workpieces to be machined by the tool. This value
and, if necessary, a prewarning limit must be stored in consecutive P memories. If the value
"9999" is entered, the monitor is not active for the selected tool. The monitoring function is
carried out by FB 157 "Workpiece count/prewarning limit".
When the tool is inserted (BEAR=1), the workpiece count is decremented and bit 4 set in
DB 152 "Workpiece count already decremented". This ensures that the workpiece count is
decremented only once for the machining of a workpiece.
If the number drops below the prewarning limit, bit 0 is set in DB 152 "Prewarning limit
reached". If the workpiece count is 0, the tool is disabled immediately or at the end of the
program depending on the parameter assignment of function block FB 157.
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SINUMERIK 840/880 (PJ)