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6F3B0250
Basic Hardware and Function
241
7. Instructions
·
Manual mode
In this mode, the manipulation value MV can be directly controlled by the input value of MMV.
MV differential limit for manual mode DMMV is effective. MH/ML and DMV are not effective.
When mode is changed from manual to auto or cascade, the operation is started from the current MV.
·
Cascade mode
This is a mode for PID cascade connection. PID is executed with CSV as set value.
Different from the auto mode, set value differential limit is not effective. Manipulation value upper/lower limit
MH/ML and differential limit DMV are effective.
Bump-less changing from cascade mode to manual mode is available. (Manual mode manipulation value
MMV is over-written by current MV automatically. MMV
¬
MV)
And, bump-less changing from cascade mode to auto mode is available. (Auto mode set value ASV is
over-written by current CSV automatically. ASV
¬
CSV)
·
MV tracking
This function is available in auto and cascade modes. When the tracking designation (
A+5
bit 2) is ON,
tracking input TMV is directly output as MV.
Manipulation value upper/lower limit MH/ML is effective, but differential limit DMV is not effective.
When the tracking designation is changed to OFF, the operation is started from the current MV.
Note
·
PID3 instruction is only usable on the main-program.
·
PID3 instruction must be used under the constant scan mode. The constant scan interval can be selected in
the range of 10 to 200 ms, 10 ms increments.
·
The data handled by the PID3 instruction are % units. Therefore, process input value PVC, manipulation value
MV, etc., should be converted to % units (scaling), before and/or after the PID3 instruction. For this purpose,
the function generator instruction (FUN165 FG) is convenient.
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