Ny-Series Instructions Reference Manual (W560 - Omron NY532-5400 Reference Manual

2 Instruction Descriptions
PresentSP (Present Set Point)
Present set point PresentSP is the set point in the present task period. For example, assume that the
user sets the set points for 0, 10, 40, and 60 minutes after the start of control as shown below. Also
assume that the current time is 30 minutes after the start of control. The AC_StepProgram instruction
performs linear interpolation of the set points for 10 minutes and 40 minutes after the start of control
and calculates PresentSP.
PresentSP
Set point
0 10
PredictSP (Predicted Set Point)
Predicted set point PredictSP is arrived at by applying delay compensation for 2-PID control to present
set point PresentSP. If PresentSP is passed to SP in the PIDAT instruction without compensation, PV in
the PIDAT instruction will not match the set point. This is illustrated in the following figure.
PresentSP
Control value
0
The set point that can been compensated for delay is given by PredictSP. The AC_StepProgram
instruction calculates PredictSP based on integration time IntegrationTime and 2-PID parameter α
Alpha. By passing PredictSP to SP of the PIDAT instruction, the tracking characteristic of programmed
control with the PIDAT instruction is improved.
Control value
PresentSP
0
2-772
User-specified set points for 0, 10, 40, and 60 minutes
Time [min]
30 40 60
(Current time)
Set point
Process value
10 30 40 60
Set point
PredictSP
Process value
Time [min]
10 30 40 60
Time [min]

NY-series Instructions Reference Manual (W560)