The inst I was referring to is an object id like the one returned from dbCreateInst. There are several ways to get the object id:
1. inst = dbCreateInst(cvid mstr nil x:y "R0" 1)
2. inst = dbFindAnyInstByName(cvid "U78")
3. Select the instance in the cellView and then do: inst = car(selectedSet())
You need to understand the difference between the objects and their names and in the case of parameters, their prompts can be different from the names. Just as you can't do "U78"~>, you also can't do "Total Width"~>. The reason I sent you the sample procedure called "mysel" was to show you how to identify the the parameter name so you can access the parameter object.
cdfGetInstCDF is going to return an object id for the cdf, it is not going to return a string. Try loading and running the procedure I sent. Hopefully this will clarify some things for you. Load the code in the CIW, select the instance in your schematic and then run mysel() in your CIW.
cdf = cdfGetInstCDF(inst)
This will get the cdf for the instance object id stored in the variable called inst. From this cdf object id, you can then obtain other information from its attributes and properties. To see what is availble on that object id, do the following in your CIW:
If the inst you are referring to is a pcell with a cdf, you should see a list of object ids when you do ~>? and a list of lists of each object's attributes and values when you do ~>??.
Let's say you have a cdf and one of the prompts is "Total Width". You can get this specific parameter from the cdf this way:
tw = car(setof(x cdf~>parameters x~>prompt=="Total Width))
The setof command looks at all the parameter ids and finds the one with a prompt attribute equal to "Total Width". It returns this parameter in a list, so we take the car of it and store it in a variable called tw. Now, you can get its name:
Once you know that name, you can access it directly on the inst id. Lets say the name of the "Total Width" parameter is "totalWidth", then you can do this:
Do some playing around until you get comfortable with object ids.