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« on: July 12, 2006, 02:30:00 PM »
I am in the process of planning to network four T100MD+ PLC's that are running product test stations.
The aim is to have the PLC's report their test results back to the intranet and have results saved in a file on the network.
If I connect the PLC's together on a RS485 connection and then use a X-Server module to connect to the intranet then the PLC's can be accessed by TLServer on the intranet - so far, so good.
The next bit I'm unsure of.
To collect information from the PLC"s I think there are two options that I'm aware of:
1 - Use Tri-Excel link to query the PLC's and read variables from them. However I only want the information to be collected once the PLC has completed a test, Tri-Excel link only appears to collect information on a timed basis (eg every XX seconds). How do I make the information collection conditional on completion of test? Would this condition have to be tested in Excel via a macro? eg collect info every 10 sec and look for a test complete flag, if flag is up then paste last data collected into spreadsheet, otherwise ignore
2 - Use file service requests from the PLC to append data to a text file. This looks like a good solution but I am concerned that the manuals do not give an example of file services going out thru port #3 (RS485). Can I use file service requests on the RS485 network via the X-server to append files on the intranet?
Or is there another way?
Regards
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