Little Endian or Big Endian with Modbus TCP?

[daniel.ponader]

Dear All,

unfortunatelly we have a little problem to establish communication between WinCC OA 3.10 and a Sentron PAC 4200 Multimeter over Modbus TCP. The data format of double integer values of the PAC is Little endian, the WinCC OA reads the value as big endian :

e.g.

Value sent by PAC : 1 , 00000000 00000000 00000000 00000001
Value read by WinCCOA: 65536, 00000000 00000001 00000000 00000000

Is there a possibilty to change the endian format? We tried to change the "endianity" value of the internal DP (_Mod_Plc) but this was not successful.

Thanks a lot for your support

[Gertjan van Schijndel]

The '_Mod_Plc.Endianity' internal datapunt element is not used since 3.9 anymore. It has been replaced by the config file entry 'littleEndianRegister'.