ReadMultiVars callback not triggering

[DJWassink]

the function S7Client.ReadMultiVars(multiVars, [callback]) doesn't seem to trigger the callback. The method itself seems to be working fine in a blocking manner (without the callback). But when I specify the callback it simply never triggers.

Here a example of the issue:

var items = [{
  Area: 132, WordLen: 4, DBNumber: 2, Start: 24, Amount: 1
}, {
  Area: 132, WordLen: 6, DBNumber: 2, Start: 46, Amount: 1
}];

s7client.ReadMultiVars(items, function (err, res) {
  console.log('callback triggered');
  if (err) {
    log.error(err);
  } else {
    log.info(res);
    processSessionReadItems(res);
  }
});

Am I simply doing something wrong or isn't it implemented yet? The documentation about this function isn't documented either, so my excuses if it isn't ready yet.

[mathiask88]

Hi, no you are not doing something wrong, the async part of this function is not implemented yet. I got some time this weekend and I think I can add this. And yes the docs are a bit messy and quite a spot of work :/

[mathiask88]

@Lailend Sorry for the delay. I added all the missing functionality(not only ReadMultiVars) in the client and now I have to update the docs. I hope I can push the changes to master within the next week.

[DJWassink]

@mathiask88 No problems! I am already happy that you take the effort to do this. So thanks so much really appreciate it!

Is the S7Client.ReadSZL() also by any chance implemented in the next push?

[mathiask88]

Is the S7Client.ReadSZL() also by any chance implemented in the next push?

Yes, every client function should work. I pushed my WIP to master so you can test a little bit, before release and while I am updating the docs. To do so you can add the repo to your package.json(https://docs.npmjs.com/files/package.json#git-urls-as-dependencies). For your information: ReadSZL(ID, Index, [callback]) and returns a buffer.

[DJWassink]

Awesome really impressed. Really gratefull for the fast help and WIP push. Will defenitely try a few of these new functions out!

[mathiask88]

I am happy about feedback ;)

[celevra]

hi,

thank you very much for this library. isn't it possible to use s7client.S7AreaDB and s7client.S7WLBytes in ReadMultiVars as like this:

var items = [{
  Area: s7client.S7AreaDB, WordLen: s7client.S7WLBytes, DBNumber: 1, Start: 0, Amount: 1
}, {
  Area: s7client.S7AreaDB, WordLen: s7client.S7WLBytes, DBNumber: 1, Start: 2, Amount: 1
}];

regards

[mathiask88]

hi @celevra, yes this is possible and recommended.

[celevra]

thank you for your fast answer, but if i try it like this:

var items = [{
  Area: s7client.S7AreaDB, WordLen: s7client.S7WLBytes, DBNumber: 1, Start: 0, Amount: 1
}, {
  Area: s7client.S7AreaDB, WordLen: s7client.S7WLBytes, DBNumber: 1, Start: 2, Amount: 1
}];

s7client.ReadMultiVars(items, function (err, res) {
        if(err) return console.log(' >> ReadMultiVars failed. Code #' + err + ' - ' + s7client.ErrorText(err));

        console.log(res);
});

i get

/node/s7/snap.js:32
        s7client.ReadMultiVars(items, function (err, res) {
                 ^
TypeError: Wrong argument structure

what would be the correct argument structure?

i plan to use your library intensive so, if you don't mind, i would create an examples directory to show others how to use the function calls

[mathiask88]

Yes, the error is correct because you got a typo in s7client.S7WLByte . I didn't see it either two days ago, sorry for that! I am currently updating the readme, but I don't got much time at the moment. An example directory sounds great.

[celevra]

ah ok, now it's working. Thank you! overall in the doku is s7client.S7WLBytes ;-)