Max and Min values

I am programming a PLC5 and have come across a problem that the customer has requested. The customer requires me to monitor a thermocouple value and at the end of a set period i need to display the minimum and maximum thermocouple values, and i cannot think of an instruction that will look at the value and store in an integer file tha max and min values over a period of time.

Thanx in advance for any responses.

Paste this into RSLogix

(change the adresses to suit your program)
n7:0 = Analog value
n7:1 = Stored minimum value
n7:2 = Stored maximium value

LES N7:0 N7:1 MOV N7:0 N7:1

GRT N7:0 N7:2 MOV N7:0 N7:2

add some logic to reset the min and max values.

Yes so simple thnx for your help

I don't know about PLC5, but I have the same thing in an SLC and I have to wait until all my NT8 inputs to come online so to speak to not capture negative values when the SLC first starts.

Also, I capture the min value when the input is less than AND not equal to the minimum and I use a oneshot before the move. That way, it will continue to record the minimum every time it is below min and changes. Same for the max.