PID Structured Text Program Example

This Structured Text example shows a use of Auto-Tune and PID control for LOOP 0.

Notes:

  • Block Value for PID function blocks will always be 0.

  • See XG5000 help file for PIDAT status information.

  • See XG5000 help file for PIDRUN status and error information in the for XEC table.

  Variable Kind Variables Type Address Initial Value Retain Used

EIP/
OPC/
UA

 HMI Comment
1 VAR D0_Saved_Value REAL   0 ✓ ✓     D value from auto-tune for PID0.
2 VAR Enable_PID0 BOOL       ✓     Command to enable PID0.
3 VAR I0_Saved_Value REAL   0 ✓ ✓     I value from auto-tune for PID0.
4 VAR INST_PID0AT PIDAT       ✓     Instance of auto-tune function block.
5 VAR INST_PID0RUN PIDRUN       ✓     Instance of PID0 run function block.
6 VAR INST_R_TRIG R_TRIG       ✓      
7 VAR P0_Saved_Value REAL   1.0 ✓ ✓     P value from auto-tune for PID0.
8 VAR PID0_AutoTune_Completed BOOL     ✓ ✓     Status that auto-tune has been done for PID0.
9 VAR PID0_AutoTune_Stat WORD       ✓     Status word of the auto-tune function.
10 VAR PID0_Status WORD       ✓     Status word of PID0.
11 VAR Program_Step USINT   0   ✓     Program step for PID0.
12 VAR Rising_Edge_Autotune BOOL       ✓     Rising edge of auto-tune command
13 VAR Run_Auto_Tune BOOL       ✓     Command to run auto-tune.
14 VAR_EXTERNAL _04_CH0_DATA WORD %UW0.4.2     ✓     Analog input module: CH0 output.
15 VAR_EXTERNAL _05_CH0_DATA WORD %UW0.5.3     ✓     Analog output module: CH0 input.
16 VAR_EXTERNAL _05_CH0_OUTEN BOOL %UX0.5.32     ✓     Analog output module: CH0 output enable.

 

 

 

 

 

LP109-4