telemecanique AEM 811 problem

[chrisk 0]

We have a few of machines using an AEM 811 analog input card, which is a intelligent module with its own processing capabilities such as input configuration for each channel as well as scaling and threshold detection. According to the documentation the card should function as follows. After power-up a default configuration is loaded and status bit is set indicating a default configuration is loaded. The program then stops the card, transfers the required configuration via a text-block exchange. If the card receives a valid configuration is sets a status word to 'FE' and clears the default bit and the waiting for configuration bit. It should also set a text-block bit to one indication a successful transfer of the configuration data. The program can then re-start the card and begin using the acquired input data. Everything appears to be working except the text-block bit indicating the receipt of the configuration data. This will not allow the card to start. We have three machines which are identical in this regard and we have two spare cards. The spares will work in the other two machines and their cards work also, but none of the cards will work in the third machine. This card sits in slot zero adjacent to the PLC and we have tried changing the backplane with no joy. This is driving me absolutely bonkers. A can't seem to locate many resources familiar with Telemecanique. Does anyone have any ideas? TIA Chris