need help with ADM2484E

Have received a problem at use ADM2484E - the starting bit turns out with  "step". The circuit drawing and signal photo in the appendix. In the photo:

- blue signal (3) - transmission enable - pin 5 DE ADM2484E

- green (2) - TxD signal on 6 pin of ADM2484E

- yellow (1) - RS485 line signal (DATA+ pin 14 ADM2485E)

Thanks!

attachments.zip
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  • 0
    •  Analog Employees 
    on Nov 14, 2011 10:03 PM

    Hello Yuri,

    Apologies for the delay in getting back to you.

    The ADM2587E does not have a "sleep mode". With the ADM2587E driver and receiver inactive, the digital isolation (signal and power) components of the device remain active.

    Your earlier oscilloscope plot only has DATE+ captured, can you confirm that DATE- is not also high during the "error" interval? (Ideally could the same plot be captured with DATE-?)

    I mentioned any potential auto-transmit/auto-direction feature of the other nodes previously, as such a feature may not have been designed for compatibility with a 3.3V powered transceiver. The ADM2484E driver output levels are lower than for a 5 V powered transceiver (e.g. ADM2491E) and correspond to the 3.3V operation on Vdd2.

    Regards,

    Conal

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  • 0
    •  Analog Employees 
    on Nov 14, 2011 10:03 PM

    Hello Yuri,

    Apologies for the delay in getting back to you.

    The ADM2587E does not have a "sleep mode". With the ADM2587E driver and receiver inactive, the digital isolation (signal and power) components of the device remain active.

    Your earlier oscilloscope plot only has DATE+ captured, can you confirm that DATE- is not also high during the "error" interval? (Ideally could the same plot be captured with DATE-?)

    I mentioned any potential auto-transmit/auto-direction feature of the other nodes previously, as such a feature may not have been designed for compatibility with a 3.3V powered transceiver. The ADM2484E driver output levels are lower than for a 5 V powered transceiver (e.g. ADM2491E) and correspond to the 3.3V operation on Vdd2.

    Regards,

    Conal

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