Mitsubishi Electric MELSEC-Q00U(J)CPU User Manual page 190

(e) Sampling trace registration while the trigger condition is met
Even if a trigger condition is met, the sampling trace setting can be registered by the following procedure.
1.
Turn on SM829 (Forced registration specification of trace setting).
2.
Enable the forced execution registration.
[Debug]
For the above case, start the trace in the status where the trigger condition is not met. If the trigger condition is
met, the trigger may not be normally executed.
(f) When a file register is selected
When a file register is selected as a specified device for a trace setting, do not change the file register file and
the block number of file register after trace registration. If doing so, trace data may not be normally collected.
(g) Data acquisition timing setting
When the data acquisition timing setting is set to "Specified Interval" or "Each Multiple CPU High Speed
Transfer Cycle", pay attention to the sampling interval and sampling processing time for one sampling because
the sampling trace is performed as interrupt processing. If the processing time for one sampling is long, "WDT
ERROR" may occur.
(h) Performing sampling trace during execution of another sampling trace
The first sampling trace is performed normally. The second sampling trace cannot be performed.
(i) Executing online change
When sampling trace and online change are performed simultaneously, they operate as follows.
• Performing sampling trace during online change
• Performing online change during execution of sampling trace
(j) Latch clear by using the special relay and special register areas during execution of
sampling trace
The latch clear operation is performed normally. However, the sampling trace will be stopped.
188
[Sampling Trace]
• When the trace point or trigger point is specified by the step number:
The online change is completed normally but the sampling trace is not performed.
• When the trace point and trigger point are specified by setting other than the step number:
Both the online change and sampling trace can be performed.
• When the trace point or trigger point is specified by the step number:
The sampling trace is suspended but the online change is normally performed.
• When the trace point and trigger point are specified by setting other than the step number:
Both the online change and sampling trace can be performed.
[Forced Execution Registration Effective]