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Samba Modbus connection to SEW VSD

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I am trying to connect a Samba PLC to a SEW MDX61B VSD via  Ethernet and using Modbus TCP.  Using the function blocks in the Samba program I can get it to connect to the SEW  VSD but when I try and read an address which the SEW guys say is correct, 8320 which is the encoder position it shows a status fault code of 7. I can connect the same program to a Jazz PLC and read an address in it.

The Samba is the Master and SEW the slave, can someone help, I think it looks like a case of just the wrong address or maybe an extra number before it

Thanks Phil

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Have you reviewed how VisiLogic  Handles Modbus register addressing?

MODBUS Help is hard to Find in Help, but start here:   ( there is a lot of info there- just well hidden )

                                                                  Help, Index,   MODBUS

  Find and look at Slave Addressing.  Notice the SAMBA ( Vision Color) addressing is  set up in HEX ( Base 16)

     Know how to convert  Decimal to Hex and   back   -- Unitronics will do it automatic , but beware !

          in the example illustrated     7028  is Hex  0x7028     =   28712 decimal

     So is  8320   Decimal or Hex?          8320 Decimal =   0x2080 ( H-2080)

                                                                                0x8320 Hex      =     -31968 decimal    ( MI's are Integers  +/-  32767)

   Just something to consider



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