Hi guys/girls,
Was wondering if anyone had any ideas on the following:
I'm designing a switch using a thermocouple and a PLC. What this is meant to do is turn on and off at particular values, i.e. at +60 it turns on, +70 it turns off, -60 it turns off and -70 it turns on (this obviously equates to some current/voltage).
The PLC software included makes use of logic gates (AND, OR etc) and arithmetic. So what I did was use an R-S flip flop to check the input and if it meets one of the criteria, set it either to on or off.
The problem however is the initial conditions, since you don't know if initially the temp is rising or falling. If for example the temp is above 60 and rising, the switch should be on initially, if its more than 60 and falling, it should be off etc.
Any ideas on what I could do to set the initial conditions?
Thanks in advanced
Was wondering if anyone had any ideas on the following:
I'm designing a switch using a thermocouple and a PLC. What this is meant to do is turn on and off at particular values, i.e. at +60 it turns on, +70 it turns off, -60 it turns off and -70 it turns on (this obviously equates to some current/voltage).
The PLC software included makes use of logic gates (AND, OR etc) and arithmetic. So what I did was use an R-S flip flop to check the input and if it meets one of the criteria, set it either to on or off.
The problem however is the initial conditions, since you don't know if initially the temp is rising or falling. If for example the temp is above 60 and rising, the switch should be on initially, if its more than 60 and falling, it should be off etc.
Any ideas on what I could do to set the initial conditions?
Thanks in advanced