collecting data from scales

Hi,
I have a project and I'm looking for options for collecting data from any Mettler scales (model hasn't been picked yet).
The process sequence is:
1. Scales receives a high "1" output from Micrologix 1200 and weighs the product.
2. Scales sends this data to the database or excel (any format .xls, .csv)
3. After 3 samples PLC sends a high "1" output to the database or excel to start a new line.
I would like to receive a data in the folowing format:
----------------------------
date | sample 1 | sample 2 |sample 3 |
15.01.2008 | 100 kg | 155 kg | 25 kg |
16.01.2008 | 160 kg | 15 kg | 45 kg |
17.01.2008 | 170 kg | 154 kg | 55 kg |
----------------------------

Any solutions welcome

Thanks
Regards
Mike

Glideratio:
If you have the chance, change your PLC system to ML1500, install a devicenet scanner 1769-sdn and gather weigh data from scales. Mettler has models with devicenet interface also hardy instruments has scales with devicenet interface.

I´ve done it in the past with great success.

I second moving to either a Micrologix 1500 or Compactlogix L23 (larger scanner memory size) to take advantage of the devicenet scanner to gather your information to the scale controller. Mettler's devicenet config is very easy to use.

how do I then transfer the data from PLC to excel. As I understand I will need a OPC server for getting the values from PLC to PC and then an custom VB application to transfer data from OPC to excel ?!

You can use a computer running RSLinx Classic and perform a DDE or OPC transfer directly into Excel from the PLC over ethernet (L23E comes with ethernet port built in). There are many other ways to do this as well. This is just one easy one I had off the top of my head.

Guys,
would this scheme work ?

|SCALES|<---rs232---->|PC|<---rs232--->|PLC micrologix 1200|

I'm not going to say it won't work but it certainly will not be easy. Especially if you have a lot of scales or if there is a great distance between any scale to the PC or PC to the mircrologix. You will have to do a lot of custom programming (in excel?) to retrieve the information from the scale to the PLC and format it.

If you do not need the data in your PLC then just send it directly out a RS-232 to the PC storing the data. Use the digital I/O on the Metter to allow it to be comanded by the MicroLogic PLC. Unless you have a really complicated batching system you not going to need but a few I/O.

Hint I would program a handshake between the PC and the Scale controller and use this to control an output going from the scale to the PLC. That way the PLC does not comand another batch start until your sure your PC has the data from the last batch.

You could easily do it with Kepwares UCON driver gathering data from the Scale on the RS232 port once the data is collected into tags you can then use any OPC or DDE interface to get the data into any type of client. You can check itout at http://www.kepware.com.