Hello all, after looking through various threads ive struggled to fing what i require Im currently measuring a 4-20mA signal from a pressure transmitter, which is scaled 0-500pascals on a TD display and it also runs a PI loop on an inverter via the LOGO. I now need to use the 4-20mA signal to carry out this function:
#1 activate a output to close a valve via a Digi Output, I can do this
#2 Activate my inverter to go to a set speed eg 5v output from LOGO, i can do this
#3 After a set time close another valve via a Digi output, i can do this
#4 After a circa 5second dealy, read the pressure transmitter signal and store it-I cant do this!
#5 Start a timer for lets say 90seconds
#6 After that time, check the analogue value and store it.-i cant do this!
#7 Compare the two analogue values and if analog1-analog2 is less than a preset value, display PASS on TD display If analog1 -analog2 is more than the preset value display FAIL on TD display

I hope someone can help as im having no luck Im avoiding moving to a S7-1200 at this stage
thanks