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skylight
04-02-2007, 03:34 AM
As a matter of interest, would there be a conflict using the RFID reader at the same time as outputting to the PLX-DAQ software?

I'm thinking of using the reader and a BS2 to send data to Excel, information such as Employee ID and what Date and Time the employee tried to access a restricted area. I have written a simulation of the data from the reader(not purchased one yet)·to check the output in Excel· but as an afterthought i was concerned that the serial lines only like to talk to one device at a time, does the RFID reader·allow a busy signal so that it takes priority until it's finished sending the data to the stamp and then the stamp allows PLX-DAQ to read and send this data to Excel?

Although unlikely to happen in practice, could a rapid reading of two tags one straight after another corrupt the first tag's data·still being sent to PLX-DAQ? Is there a buffer in the reader?

Unsoundcode
04-02-2007, 07:29 AM
Hi skylight, if your configuration is RFID------> Stamp-------> PC I dont see there would be a problem with your serial link. The Stamp can only process one instruction at a time, so the sequence would be

1. Read tag and send to Stamp

2. Stamp identifies tag and transmits to PC

3. PC logs and manipulates data

the RFID would use one pin of the Stamp for serial data in and the Stamp to PC would probably use the programming port (pin 16).

The Stamp should be programmed to see an error in the event of a bad tag read and prevent the error from being sent on to the PC.

Jeff T.

skylight
04-02-2007, 02:55 PM
Thanks for putting my mind at rest, I hadn't thought about any errors occurring, will have to work out some code to cope with that.
Sorry for the long delay in replying, i'm·8 hours ahead of you.


Post Edited (skylight) : 4/2/2007 8:04:12 AM GMT