read weighbridge data through Com port (serial port) in SAP PCO

[ankit12]

Hi Experts,

we are having an requirement where PCO need to read data through comm port (serial port) as we cannot use ethernet convertor or any device to convert the data coming through Weighbridges as per govt. norms.

So can you please help us understanding:

1. If PCO can communicate to Weighbridge using the COMM port.
2. If yes, then how it can communicate and what are the pre-requisite for this.

Quick help is appreciated.

Regards,

Ankit Gupta

[Kevin_Hunter]

Hi Ankit,

You haven't provided enough information to provide a definitive answer however let me discuss the options.

If the RS232 port is streaming raw weight measurements as ASCII text then no PCo does not support this out of the box, if the data is being send as Modbus RTU data then yes PCo does support this out of the box.

Most weigh scales I have have worked with stream the data as ASCII text so I typically use a RS232 to Ethernet serial server which you mention that this is not allowed due to government norms, can you explain this further as this is quite an unusual statement.

Your options are to write a custom PCo source system for this weigh scale (not difficult if you can write C# code), use an off the shelf translator such as Kepserver (the UCON driver may work for you), write a custom app to convert the serial stream into a socket stream.

However each of these methods is basically doing the same as the hardware adaptor so would also not be allowed based on your statement about the government.

My guess is that you are misinterpreting the rules about what you can connect to the weigh scales, I could understand not allowing any device that can manipulate the measurement data but if the device only changes the transportation method (RS232 - Ethernet) then what is the issue ?

Thanks

Kevin

[ankit12]

Hi Kevin,

Thanks for detailed explanation.

We have double checked with our client and confirmed that we can't introduce any device between Weighbridge and local computer even if its just transforming the data from one format to another.

This leaves us only one option which is RS232 port to read the data. So can you please suggest if there is any way to have an OPC server which can read the data from RS232 port.

IF any other option is there to get the data from RS232 port to SAP PCO application please let us know.

Quick response is appreciated.

Regards,

Ankit Gupta

[Kevin_Hunter]

Hi Ankit,

If there is only one RS232 port and its already connected to a computer then you will have to install an RS232 splitter then write a custom app to convert it to OPC UA . I wrote a couple of blogs covering how to do that with mettler toldeo weigh scales, you can use a similar approach.

https://blogs.sap.com/2021/09/27/integrating-mettler-toledo-weigh-scales-to-sap-digital-manufacturin...

https://blogs.sap.com/2021/10/04/integrating-mettler-toledo-weigh-scales-to-sap-digital-manufacturin...

Thanks

Kevin

[steve_stubbs]

Hi Ankit,

You can use the KEPServerEX OPC Server with the Mettler Toledo Serial Driver that will communicate directly with the scale over a COM Port (Or Ethernet). The server is an OPC UA Server that PCo can connect to directly, and exposes 13 tags related to the scale. However, you will need to install PCo and the OPC Server on the same PC if you are restricted from transporting the scale data as OPC data to PCo. RS-232C cable lengths are limited to 50 ft for 19.2K baud rates; there are some special cables that may be able to extend the distance. You can also use RS-232 to RS-422 converters to get extended cable lengths.

Regards, Steve