System Identification Assistant Signal Generator

[SPV1955]

Hello,

I am using a GW Instek power source to heat a graphite rod within a vacuum chamber.  I am detecting the temperature with a K type thermocouple connected to a thermocouple input module.  I have written a labview program with a PID and have everything running, yet i force tuned the PID. I would like to use the signal identification tools labview provides to identify the transfer function and model the process.  I have used the system identification assitant in attempting to send a step signal and acquire a response, yet I have been running into difficulties.  The only way I can perform a step function is to manually generate an output of a specified power and then measure the response, as the signal generator within the system identification software is not identifying the GW Instek PSW 30-108 power source. With manual input and importing both input and output data i am able to get a parametric model, yet the transfer function provide me PID values which are 5 orders of magnitude greater then the ones i am currently using. Ideally i would like to use the software to generate the signal and measure the response continuously rather then using data i collect through my program.  If possible, I would also be interested in perhaps directly integrating VI's to perform signal analysis directly into my process program.

Problems and what I have done:

I have the drivers for the power source and my process program recognizes the device yet system ident assist cannot find the hardware. I have attempted to creat a task in NI-MAX yet the hardware is also non-identifiable. 

Port module input works with VISA and this is how my VI is communicating with the power source.

Goals:

I would like to use the system ident assist to generate power ouput and collect temperature input, and generate a process model, so that I may tune my PID more accuratly.

Also, I may be interested in integrating VI's directly into my process program, yet I am new to the LV language...

I have attached  my Labview program below.  I would like to thank you in advance for your time and look forward to responses.

Cheers

[JuliaO]

Double post, for further Information see http://forums.ni.com/t5/LabVIEW/System-Identification-Assistant-w-o-NI-Signal-Generator/m-p/3014731#...