Connecting a Sartorius scale to an Allen Bradley PLC

[JaredZ]

Hello,

I am trying to connect a Sartorius Combics 3 scale (model CAIS3-U) to an Allen Bradley ControlLogix5661 PLC using an Ethernet connection. I've configured the scale for the appropriate IP address and can ping it. There's a menu for Ethernet mode that has several different settings to use including SBI, XBPI, and Modbus/TCP. Initially I thought I would have to use Modbus/TCP, but it doesn't look like this PLC supports it so I'm looking at using SBI or XBPI, but can't find anything about these online. I'm also not sure how to configure AB's generic Ethernet module for this scale. It seems like the Assembly Instance for input, output and configuration could be just about anything. About the only thing I know is I can configure the scale to output 16 or 22 characters which would put the input size around 6 or 8. Searching online doesn't yield much help and the user manual isn't a lot of help either.

If someone has experience with these type of scales or just some good general advice, I would appreciate the help.

Thanks.

 

[saultgeorge]

Hey, hi and welcome to the forum. I had to add a generic input module to a PLC I was programming in a plant and one of the key configuration steps was the Assembly instance. I've attached a PDF that shows how to calculate all the data types and lengths needed to configure it, however the example is not a scale. All of that info ought to be in the manual for your scale, the values. Check it again, and good luck.

 

[JaredZ]

Hey, hi and welcome to the forum. I had to add a generic input module to a PLC I was programming in a plant and one of the key configuration steps was the Assembly instance. I've attached a PDF that shows how to calculate all the data types and lengths needed to configure it, however the example is not a scale. All of that info ought to be in the manual for your scale, the values. Check it again, and good luck.

Thanks, I'll check it out. I will check the manual again and see if it's in there.

 

[Darrenb333]

Hi Jared,

Just wondering did you find a solution to this ?

I am having the same issue here.

 

[Ken Roach]

Welcome to the PLCTalk forum community, Darren !

I suspect there's no answer here because there's no answer to be found. ControlLogix has excellent and easy-to-configure communications to other Allen-Bradley devices and products that support the EtherNet/IP industrial protocol, but not great connectivity to general-purpose Ethernet connected devices that use other protocols.

There's a "Generic Ethernet Module" object in Studio 5000 Logix Designer, and I really dislike that misnomer. It should be named "Generic EtherNet/IP Adapter".

Some scale manufacturers like Rice Lake and Mettler-Toledo have built PLC-specific interfaces for years, including modern ones that support EtherNet/IP and can connect to a ControlLogix.

I don't see any evidence that the Sartorius scales have EtherNet/IP protocol support. The SBI and XBPI selections are proprietary scale manufacturer protocols.

So that leaves Modbus/TCP, the most generic automation protocol there is. The ControlLogix implementation isn't my favorite thing to do (you have to download and use an "Add On Instruction" but it does work.

If you want to discuss your application further, please post some details like the exact model and firmware revision of A-B controller you are using, and the exact model of scale you have. As much context and "this is what I've done so far" as you can provide will be useful.

And again, welcome to the PLCTalk forum !

 

[Darrenb333]

Hi Ken,

Thanks for the reply on this.

Yes seems like sartorius offer eds files for all other protocols apart from Ethernet.

So we have a 5580 L83 using V31 firmware. Trying to connect to a combics 3 SIS unicom Ethernet adapter.

Similar to Jared's post, I can ping the device and have been able to connect to the device using webpage interface.

I have also gone down the generic Ethernet module route but was unsuccessful trying to find the correct instance settings needed to connect to it. Or finding any documentation that would indicate how to setup the device in a ab controller.

I have not used modbus/tcp protocal before could you explain ?

And once again thanks for the reply

Darren

 

[JaredZ]

Hi Jared,

Just wondering did you find a solution to this ?

I am having the same issue here.

Yes, I did find a solution to this. This is a few years old, but as I recall one of my coworkers pointed me to Rockwell Automations web site. Someone had written a Modbus driver in ladder logic and it worked pretty well. It's a third party add on so there isn't officially any support for it.

 

[Ken Roach]

Because you have a 5580 series controller, it will support "open sockets" like the 1756-EWEB and the 1756-EN2T/EN3T/EN4T do. That functionality enables routines and AOI's that perform network functions beyond the native feature set of ControlLogix.

The Modbus/TCP add-on instruction was created by RA Commercial Engineering, but it generally offered as-is without support.

You can get it from the RA Sample Code website. Log in and search on the term "Modbus TCP".

https://www.rockwellautomation.com/...ads/application-code-library/sample-code.html

In general, I strongly recommend making sure your addressing and connectivity are working using a Modbus utility (I like Chipkin Automation, others swear by ModScan32) before attempting the AOIs.