AdvancedHMI Software

General Category => Support Questions => Topic started by: msurma on September 19, 2019, 01:26:05 PM

Title: Subscribe limit
Post by: msurma on September 19, 2019, 01:26:05 PM

Subscribe seems to have a hard limit of 21 Subcribed tags.

I am using Subscribe as follows:
        public EthernetIPforCLX PLCConnection;
...
                PLCConnection.SubscriptionDataReceived += tagUpdate;  //
                PLCConnection.PollRateOverride = 500;
...
            PLCConnection.Subscribe("myTag1", 1, tagUpdate);
            PLCConnection.Subscribe("myTag2", 1, tagUpdate);
...
            PLCConnection.Subscribe("myTag21", 1, tagUpdate);

When I add one more Subscribe, the driver seems to fail, nothing seems to work correctly. The subscription data recieved starts sending error -22 (no response from PLC), direct reads and writes no longer work. What's up?

Title: Re: Subscribe limit
Post by: Archie on September 19, 2019, 01:49:43 PM

What version are you using?

Title: Re: Subscribe limit
Post by: msurma on September 19, 2019, 01:58:06 PM

The CLXDriver.dll version is 1.3.2.

I worked around the problem by creating and initializing another EthernetIPforCLX object (PLCConnection2)  and subscribing 20 tags to the first one and additional tags to the second one.

That seems to work fine. I left all other references pointed to the first EthernetIPforCLX (PLCConnection).

Title: Re: Subscribe limit
Post by: Archie on September 19, 2019, 03:45:07 PM

I am not able to replicate this. What PLC and firmware are you using?

Are the tags you have the problem with actually named MyTagxx ?

Title: Re: Subscribe limit
Post by: Archie on September 19, 2019, 04:35:52 PM

I did get a problem when using longer tag names. The driver was calculating packet length incorrectly. If you send an email to the sales email giving your receipt number and request a version update, you can get the fix to this.