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5.5 Tracking Function
5.5.3 Tracking Data
5
2) Changing the Internal Device Settings
Internal device settings are changed in the following cases:
(b) Signal Flow Memory
Signal flow memory records the operation execution result of each sequence
program step, i.e., whether each sequence program step was executed or not.
The signal flow memory information determines whether the rise, fall and SCJ
instructions will be executed or not.
1) Default Tracking Settings
By default, signal flow memory is set to be not tracked.
2) Changing the Tracking Setting
When signal flow memory has not been tracked, the rise, fall and SCJ
instructions may not function normally in the new control system after system
switching.
In order to ensure these instructions function even if system switching occurs,
change the settings so that signal flow memory will be tracked.
This setting reduces the number of internal device points that can be tracked
at a time by 16k words.
POINT
1. Precautions when disabling signal flow memory from being tracked
• Rise instruction (PLS, P, SP. )
Even if the execution condition is changed from off to on during system
switching, the rise instruction will not be executed after system switching.
• Fall instruction (LDF, ANDF, ORF, MEF, PLF)
If the execution condition is off during system switching, the fall
instruction will be executed after system switching.
• SCJ instruction
If the execution condition is on during system switching, the SCJ
instruction will jump to the specified pointer without waiting 1 scan.
2. Signal flow memory tracking capacity
Signal flow memory as much as program capacity will be tracked.
Table5.45 Internal Device Settings Change
Objective
Tracking Setting
To shorten tracking time
• Change the settings so that only the devices actually
used will be tracked.
• Divide the tracking data range into multiple blocks and
change the tracking timing for each block.
To add file register or
annunciator
Set the file register or annunciator to tracking blocks
No. 1 to 64.
Program tracking timing
to any time.
• Change the settings so that the tracking trigger of
tracking block No. 1 will be turned on and off manually.
• Divide the tracking data range into into multiple blocks
and turn the tracking trigger of each block on and off in
the program.