Nj-Series Instructions Reference Manual (W502 - Omron NJ501-1500 Reference Manual

2 Instruction Descriptions
MV
MVTrackVal
Time
MVTrackSw = TRUE
MVTrackSw = FALSE
MVTrackVal (MV Tracking Value)
2
This is the value to which MV is set during MV tracking. The value of MVTrackVal does not have to
be between MVLowLmt and MVUpLmt.
StopMV (Stop MV)
This is the value to which MV is set when the value of Run is FALSE (i.e., when execution of this
instruction is stopped).
ErrorMV (Error MV)
This is the value to which MV is set when an error occurs (i.e., when the value of Err is TRUE). If the
value of ErrorMV is not within the valid range (−320 to 320), the value of MV will be 0 when an error
occurs.
Alpha (2-PID Parameter α)
This parameter determines the coefficient of the set point filter. Refer to the description in 2-PID
Control with Set Point Filter for details. Normally set the value of Alpha to 0.65.
AtCalcGain (Autotuning Calculation Gain)
This variable gives the coefficient of the PID constants that were calculated by autotuning when they
are applied to the actual PID constants. If a value of 1.00 is specified, the results of autotuning are
used directly. Increase the value of ATCalcGain to give priority to stability and decrease it to give pri-
ority to response.
ATHystrs (Autotuning Hysteresis)
This is the hysteresis that is used in the limit cycle for autotuning. More accurate tuning is achieved if
the value of ATHystrs is small. However, if the process value is not stable and proper autotuning is
difficult, increase the value. Refer to the description of autotuning for details.
SampTime (Sampling Period)
This is the minimum value of the period for PID processing. Refer to the description of the execution
timing of PID processing for details. PID processing is not performed again until the time specified
for SampTime has elapsed since the last time PID processing was performed.
RngLowLmt (Lower Limit of Input Range) and RngUpLmt (Upper Limit of
Input Range)
These are the lower limit and upper limit of PV and SP. An error will occur if the value of the parame-
ter connected to PV or SP exceeds either of these limits. RngLowLmt must always be less than
RngUpLmt.

NJ-series Instructions Reference Manual (W502)

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