LS Industrial Systems GLOFA G7M-DR30U - Page 144

Chapter 7. Usage of Various Functions
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(3) In case of using combined function of PID operation and auto tuning
(a) PID operation explanation (with A/T function)
• Measure current temperature by RTD module then digital conversion value(0 ~ 4000) is stored.
• PID7AT instruction will calculate manipulate value (MV : 0 ~ 4000) based on the SV and PV from RTD module
and output the value in range of 0~4000 to the D/A conversion module.
• The END bit of auto tuning status device will be 1 when the auto tuning is completed, and the calculate P, I, D
constants are saved respectively in the designated value. These values become the P, I, D control constant.
Program to execute the PID operation when the END bit becomes 1.
• D/A conversion modules convert the manipulate value to analog signal (4~20mA) and input it to the actuator.
(b) PID Auto Tuning Parameter
• Target value (for G7F-RD2A)
- 1300(60℃),1350(70℃),1400(80℃),1500(100℃)
• Scan Time: 0.5 sec(input ‘5’)
• Current value: %MW4104 (conversion value of the RTD module’s channel 0)
• Ripple Type: Relay Method
(c) Auto tuning parameters
• Scan Time: 0.5 sec (input ‘5’)
• Operation Mode: 0 (Auto)
• Output Limit Value: Max: 4000, Min: 0
• Man OP range: 0 (Operation mode is set to ‘Auto’)