Let's do temperature sensing and analog input using the MODPORT Field I/O Controller.
As a demonstration, connect a potentiometer and a PT100 sensor.
1. Add channels. See the MODPORT user's manual
The final state should look like this
2. Add a POU for MODPORT access.
3. Programming using the ST language.
PROGRAM MODPORT_PROC VAR HAD0_VALUE : DWORD; TH0_VALUE : REAL; TH_ORG : WORD; END_VAR HAD0_VALUE := %IW1 * 65536 + %IW2; TH_ORG := %IW3; IF (TH_ORG AND 16#8000) = 16#8000 THEN TH_ORG := TH_ORG - 16#8000; TH0_VALUE := TH_ORG/10; TH0_VALUE := -TH0_VALUE; ELSE TH0_VALUE := TH_ORG/10; END_IF
4. And create a simple visualization.
Check the result.
Download the project file : modport_adc.zip