Experimental Physics and
Industrial Control System

"Garrett D. Rinehart" <rinehart> · Mon, 2 Dec 2002 09:43:51 -0600 (CST)

> Before getting any response(value) from the controller it has to send some
> commands and I hope to use standard records ai/mbbi/stringin/stringout 
> instead of writing a new record. How to attach the string command("#aa02cnt")
> in Ai record field to read the pressure? 

If you just need to send a command string to get the box to answer you, it's 
quite simple. Take this record to read an Omega temperature meter:

record(ai,"Omega") {
    field(SCAN,"1 second")
    field(DTYP,"Ascii SIO")
    field(INP,"@/tyGS/$(IP)/$(PORT) REAL <*X01><X01%f>")
}

The command the Omega meter needs (in the first set of "<>") is "*X01". It's 
response (in the second set of "<>") is "X01{float}". I think all you need to do 
is substitute your "#aa02cnt" in place of "*X01" in the first "<>". If your box 
echos the command as mine does, do the same in the second "<>". If it doesn't, 
just put the appropriate format descriptor in there.

ie: field(INP,"@/tyGS/$(IP)/$(PORT) REAL <#aa02cnt><#aa02cnt%f>")
or  field(INP,"@/tyGS/$(IP)/$(PORT) REAL <#aa02cnt><%f>")

Note: the "REAL" command is optional... details are within the drvAscii code.

I hope that's of some help to you. You might also find a great deal of help in 
the tech-talk archives as I've hashed a lot of this out here with Allan Honey in 
the past year.

Garrett Rinehart
Control and Data Acquisition System Manager
Accelerator Operations Group
Intense Pulsed Neutron Source
Argonne National Laboratory
9700 S. Cass Ave
Argonne, IL  60439
(630)252-6561

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System