Runtime Input Question

[Andrew Wagner <apwagner@u.washington.edu>]

Hey again, 

I'm pretty close to having my magnet ramp code implemented but I need to know how to have a record access a user defined input during run time. For instance I want to turn a dial in MEDM to set the ramp point of the magnet. So far I've implemented a database as follows: 

#Calc Coil Current 

record(calc, "Current:Coil") {
  field(DESC, "Coil Current")
  field(SCAN, "Passive")
  field(MDEL, ".1")
  field(ADEL, ".1")
  field(CALC, "LA + A*1/1200")
  field(INPA, "$(MUX):VOLT:Chan204.VAL  PP MS")
  field(PINI, "NO")
  field(EGU, "A")	
  field(SDIS, "0")
}

#Calc output and write to AG3631 Voltage programmer

record(calcout, "Voltage:Output") {
  field(DESC, "Output Voltage")
  field(SCAN, "1 second")
  field(CALC, "Voltage:Output.VAL + (B - A)*.5/1")
  field(INPA, "Current:Coil.VAL  PP MS")
  field(INPB, "Runtime Input")  # How do I link to user input?
  field(OOPT, "On Change")
  field(DOPT, "CALC")
  field(DTYP, "AG3631") 
  field(OUT, "#L$(L) $(A) @0")
  field(PINI, "NO")
  field(EGU, "V")	
  field(SDIS, "0")

}

How do I set the INPB to link to a runtime input? I've seen an example where a "dummy" AI record is linked, but I'm not sure if there is a better way. I would also like to put some protection logic in place. For instance, I would like to calculate a V_min and V_max (functions of Current:Coil) that Voltage:Output must be between in order for the OUT link to be processed. Are there any examples of how to implement this? The documentation doesn't really have any. Thanks again for your help. 

Andrew