CompactLogix: Implementing HTTP requests & XML Data Transfer via TCP/IP

[guitarguybs07]

Hello, I have a project where I need to use a CLX to communicate with a 3rd party device that exchanges data via XML formatted commands and HTTP POST/GET requests. I've done quite a bit of searching around the web and haven't really found anyone else doing this exact type of method.

Here is an example of a messages I would need to send/receive:

I know using SCADA or another intermediary device to handle the data exchange is probably the proper way to do it...but in the interest of figuring out all potential options would this also be possible with using the tcp/ip open sockets? Or is that asking for too much time and trouble lol Would using SCADA or other intermediary device to handle the data exchange be easier?

Thanks!

 

[drbitboy]

... Would using SCADA or other intermediary device to handle the data exchange be easier?

Yes.


And if the protocol is HTTPS instead of HTTP, then that becomes HECK YEAH.

 

[Ken Roach]

Welcome to the PLCTalk forum community !

This is an ideal application for some external helper software or device. We have a colleague on this forum who is one of the foremost A-B open sockets experts and I'm interested to learn if he's seen any users take HTTP traffic further than "well, probably".

If it were my system, I'd be buying a DIN-rail mounted Raspberry Pi compute module based device and doing the HTTP and XML parsing work there with the low-code Node-Red platform.

In fact, I bought one specifically for that sort of application, because it will be more reliable in the field than the handful of Raspberry Pi's littering my desk. It's a Kunbus Revolution Pi Connect, their lowest-end model. The 24V buffered power and long-life eMMC should make a huge difference in reliability compared to the hobbyist-grade devices.

In my opinion, learning Javascript and Node-Red from absolute scratch would be faster than figuring out how to do this with open sockets and ControlLogix string datatypes.

 

[guitarguybs07]

In my opinion, learning Javascript and Node-Red from absolute scratch would be faster than figuring out how to do this with open sockets and ControlLogix string datatypes.

Excellent! Thanks for that great jumping-off point. Yeah, the consensus from the people I've heard from around the web seems to be that trying to manage that type of data within the PLC itself is way to cumbersome.

I've been looking for an excuse to start learning PLC tools outside of the usual ladder/STX/SFC, etc...sounds like I found the perfect project to do it!

 

[BachPhi]

see here:

https://www.advancedhmi.com/forum/index.php?topic=2684.0