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Negative value in DNPr not coming

Bhadresh

I am trying Schneider NOR module to read data over DNPr protocol. Has anyone have tried to read negative value from NOR in CitectSCADA ?

As i am not getting value in negative. Instead its displaying 65535 like that value. I tried to read same tag in Kepserver and datatype with Short datatype and its reading negative value properly. Even Kepware also not able to read same negative value using Long/read (Which only support for Analog Input in Citect).

Any idea about this or there is limitation of driver that we are not able to read INT datatype using DNPr protocol.

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  • Good to here that you browse NOR manual for this.
    I have already gone that exercise but not success in that also.

    The same manual i have gone through today also and it clearly mentioned that we have to select data type DINT or REAL in PLC and same tag need to map in NOR.

    But when we link INT tag in NOR and read it using LONG data type in SCADA it reads positive value as good as DINT mapped. but we can not read negative value (instead we are getting 65537 something value).

    So i conclude that we can not map INT/16 bit word in NOR (if there is negative value in data) and same can not be read in SCADA. So i think driver developer should think about that KepServer can read as 16 bit data and Citect can not !
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  • Good to here that you browse NOR manual for this.
    I have already gone that exercise but not success in that also.

    The same manual i have gone through today also and it clearly mentioned that we have to select data type DINT or REAL in PLC and same tag need to map in NOR.

    But when we link INT tag in NOR and read it using LONG data type in SCADA it reads positive value as good as DINT mapped. but we can not read negative value (instead we are getting 65537 something value).

    So i conclude that we can not map INT/16 bit word in NOR (if there is negative value in data) and same can not be read in SCADA. So i think driver developer should think about that KepServer can read as 16 bit data and Citect can not !
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