LG Electronics 120S user manual Usage of Various Functions

The manipulated value is out to D/A module

Chapter 7 Usage of Various Functions

e)Program Explanation

•When the input condition M0 turns on, PID operation executes at no.0 parameter.

•PID execution status registrate D0000 and the output value of control result registrate D0001

•If SV Ramp is designated, current SV is registrate D0005

•D/A module converts the MV to analog signal and output to the actuator (power converter).

•When the input condition M0 turns off, output 0 to the D/A conversion module.

When M0 turns on,

PID operation executes at no.0 parameter

When M0 turns off,

CPU stop PID operation and output 0 to D/A module

(3)In case of using combined function of PID operation and Auto tuning.

a)PID operation explanation (with A/T function)

•Measure current temperature (-200~600°C) by RTD module then digital conversion value(0 ~ 4000) is stored to D4780

•PID8AT instruction will calculate manipulate value (MV : 0 ~ 4000) based on the SV and PV from RTD module. Simultaneously, the PID8AT instruction will calculate P,I and D parameters.

•The END bit of auto tuning status device will be 1 when the auto tuning is completed. Then, MASTER-K120S will start PID operation with PID parameters that are calculated by A/T module.

b)Auto tuning parameters

•Scan time : S_TIME=5 (sampling time = 0.5 seconds)

•SV setting : 1300(60°C ), 1350(70°C ),1400(80°C ),1500(100°C)

•Current value setting : D4780(Digital value of RTD module Ch0)

•Identification method setting : Select PRC Method

When selected, the scan time fixed to 1 sec.

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