·192·
Operating manual
CNC 8055
CNC 8055i
10.
PLC
·T· MODEL
SOFT: V02.2X
Logic analyzer
10.10.3 Run trace
Once the desired variables and trigger conditions have been selected, press the "EXECUTE
TRACE" softkey so the CNC starts capturing data.
When the selected trigger condition is met, the trigger line shown in the information window changes
colors.
While the trace is being executed, the information window shows the text "Trace status:
CAPTURING".
The trace will end when the internal memory buffer dedicated to it is full or if it is interrupted by
pressing the "STOP TRACE" softkey. While the trace is being executed, the information window
shows the text "Trace status: COMPLETE".
Data capture
The data capture takes place at the beginning of each cycle (PRG and PE) after reading the physical
inputs and updating the marks corresponding to the CNC logic outputs and just before starting the
program execution.
To also capture data while executing the PLC cycle, the "TRACE" instruction must be used.
With this instruction, it is possible to capture the data of the signals that vary with frequencies higher
than the cycle time and data of signals whose status changes while executing the cycle, but have
the same status at the beginning and at the end of the cycle.
Example of how to use the "TRACE" instruction:
PRG
-----------
TRACE ; Data capture
-----------
TRACE ; Data capture
-----------
TRACE ; Data capture
-----------
END
PE 5
-----------
TRACE ; Data capture
-----------
END
The data capture while executing the trace in this program takes place:
• At the beginning of each PRG cycle.
• Every time the periodic module is executed (every 5 milliseconds).
• 3 times within the PRG module.
• Once within the PE module.
This way, by using the "TRACE" instruction it is possible to capture data more often by inserting this
instruction at critical points.
The "TRACE" instruction must be used only when debugging the PLC program and it should be
removed once the debugging process is over.
Operating modes
The way the data is captured depends on the type of trigger that has been selected. Here are the
various types of trigger used and how the data is captured in each case: