Allen Bradley SLC5/05 and P&ID

Using RSLogix 500, I'm trying to set up a p&id in a SLC 5/05 cpu and the manual says I can't use floating point values for any of it's parameters, only intergers. I want to enter a setpoint of 8.5 in the equation via a touchscreen operator interface. Thinking I might have to do a conversion from decimal to BCD or something... any suggestions?

Most HMI solutions provides the possibility to insert "decimal places" into screen variables (tags) for example for setpoints.

For example with 2 decimal points, the integer value 12345 would be displayed as 123.45.

Check the help for your HMI software. Try search for "decimal point".

OK, first thing, PID is the control block - P&ID commonly means process & instrumentation diagram and if you say that it throws people's minds in that direction.
On point; if your setpoint will be in the range of 0.0 to 10.0, for example, store it in a float register F8:1 for this discussion. In the SLC, MUL F8:1 by 10 and store it in N7:1. This eliminates the decimal point but preserves the value. Then, using the SCP instruction, do SCP N7:1 with the range of 0 to 100 to the setpoint register in your control block woth the range of 0 to 16385 (16385 is the maximum setpoint value in the PID instruction.) So when your setpoint is at 8.5 (to use your value) the PID setpoint will be at approximately 13927. I hope this is what you were looking for.

Thanks controlsguy, I'll give that a try.
I got mixed up there in the P&ID and PID, when I was posting at the time I was actually drafting a P&ID for one of my projects...