LSIS Master-K K200S - Page 204

Chapter 15 The PID function of K200S MASTER-K
15-19
15.4.2 PIDTUN (PID auto tuning)
The PIDAUT instruction is used for getting PID parameters automatically. It calculates
optimal K (proportional gain constant), Ti (Integral time constant), and Td (Derivative time
constant), and returns the result. It occupies 19 words for its execution, so make sure the
other instructions use those devices.
xxxx : The start address of PID operation area (19 words)
Device
offset
Name Description Range
+ 0 S_TIME Operation scan time 1 ~ 100
+ 1 PV Present value of control object
+ 2 SV Set value 0 ~ 4000
+ 3 RIPPLE
Select the wave that are used for PID
parameter calculation
0 or 1
+ 4 STAT Error code
+ 5 MV Manipulation value of current loop
+ 6 P The output of calculated K
+ 7 I The output of calculated Ti
+ 8 D The output of calculated Td
+ 9 PV_OLD
+ 10 LIMIT
+ 11 ULTIMATE_TIME
+ 12 MAX_amplitude
+ 13 MIN_amplitude
+ 14 STAGE
+ 15 Region / Corrupt
+ 16 Temp_PV
+ 17 Amplitude
+ 18 Kc
System use only
1) S_TIME (Scan time)
The scan time in PID operation means the interval of sampling the present value (PV). In
general, the PID operation shows best performance when the S_TIME is synchronized
with external enable input. (The input condition of PIDAUT instruction)
The range of S_TIME is 0.1 ~ 10 seconds. However, when input S_TIME data into PLC
device, it is scaled up 10 times for more precise setting. Therefore, the actual range of
input data is 1 ~ 100.
PIDTUN xxxx