Beckoff TwinCat communication

I am creating an application using Labview and I'm trying to populate some variables in the PLC. I went to beckoff's website to download the "TwinCAT ADS Communication Library". This software is suppose to be free but when I try to install it, it asks for a serial number. I just cant get around it. Any advice?

jonfarrugia said:

This software is supposed to be free but when I try to install it, it asks for a serial number. I just cant get around it. Any advice?

Click to expand...

It is free, but you have to contact support for the serial number. 877-TWINCAT

Thanks!

I have another question. Do these drivers communicate directly with the plc hardware or to TwinCAT. If this is a dumb question, I am very new with twincat!

jonfarrugia said:

Do these drivers communicate directly with the plc hardware or to TwinCAT.

Click to expand...

TwinCAT is essentially a service that runs on the Windows XP and CE platforms with exception of the smaller controllers. For instance, if you have a CX1020 with a TwinCAT runtime on Windows CE, then the TwinCAT service running in the background listens on a TCP port for incoming commands.

The drivers in the communication library communicate with the service via the ADS/AMS protocol. There are multiple versions of the driver including DLL, ActiveX, scripting, and .NET

Hopefully I didn't make that too confusing.

Of all the protocols available, which one would be the best one to use for a distribution type application?

Hi jonfarrugia, are you talking about distributed controllers, or distributed IO blocks without any intelligence? ADS messages can be sent over TCP IP to either type of device with the ADS Communications library, but the other issue is latency.

The ADS Communications library isn't nearly as fast as TwinCAT IO, because it doesn't contain the Real Time software. Are you just doing data collection, or do you require sub-second update times for control of distributed IO?

The app will talk with the beckhoff I/O manily for data collection.

I've been considering the ActiveX method because it seems to be the easiest. I am however looking for a manual that describes all the methods associated with the beckhoff activeX control. Does anyone know if such a document exists?

Since you are doing Data Collection and speed isn't an issue, the ADS Communications Library should be fine.

The documentation for the ADS Interface is all online here...
http://infosys.beckhoff.com/content/1033/tcadscommon/html/tcadscommon_intro.htm

The section below contains samples. The Beckhoff Information System is also available for download and offline viewing here...
http://www.beckhoffautomation.com/english/download/tcinfo.htm?id=70997977100337
It's quite a large file, but it's faster to navigate than the website.

ADS latency

Hi, I am new to PLC/TwinCat programming, and have a problem with ADS communications. I have a simple application (C++, .Net) in which I have a Slave following a Master with a GearRatio that is varied every 5 to 6 ms. I am using ADS WriteAny to change the GearRatio. But strangely, the motor does not respond for about 3 to 4 seconds. When it starts, it seems to make rapid speed changes, every 5 to 6 ms.

Reading back the value immediately after writing gives the correct values, right from the beginning. Only no response from the motor, initially!

Any help in solving this will be greatly appreciated.

Thank you!