Browse only one or a few DBs

[StefanoRivolta-Previero]

Is it possible to Browse only a single DB? Because when I use conn.Browse() it takes up to 15 seconds to get a response, and I feel like it's a bit too much. I need to browse only one DB, is it possible to do it in a faster way?

[thomas-v2]

You can take a look at the code of the GuiBrowser. It loads only the symbols of the DB when you expand the tree element of the datablock. But to get the symbols of a DB you need the relid for access, which is read out directly after connecting to the plc.

[StefanoRivolta-Previero]

I've looked at it, but I have an issue. Essentially I need the byte offset for the optimized DB, since I intend to read the whole DB as a raw byte array, and then unpack it. What I found is that getTypeInfoByRelId() only gives you the address relative to the parent.
I could work with it, but I've seen that if I use Browse() it will give me the address relative to the whole DB.
Would it be possible to get the whole list of symbols in a DB with the right offsets? If not I can manage, I think

[thomas-v2]

Your idea was discussed in issue #62.

The tagdescription of a struct has fields like "Nonoptimizes structure size" and "Optimized structure size". The same value can be found in the typedescription of the type itself in the attribute "TI_TComSize". There you can calculate the startoffsets if you have arrays of structs for example.

Unusual is to get the bitoffsets for bools and bool-arrays. You have to calculate them on your own. And not all bools have bitoffsets, some bools take 1 byte in memory, but e.g. bool in IEC_Counters are only a bit and have a bitoffset. You can find all the informations about this in the bitinformation attributes.

And all depends on if the DB is optimized or not optimized.