How to change the Modbus word/byte order in a SCADAPack x70 acting as a Modbus server

It may be desirable to change the word or byte order of objects when the SCADAPack is acting as a Modbus RTU Server or Modbus TCP Server. This mainly concerns Modbus floating point point and signed/unsigned Modbus double registers.

This is accomplished in the Modbus -> Server -> Advanced Configuration of RemoteConnect

Parameter	Parameter Description	Setting	Setting Description
Byte Ordering for 32-bit Values	Determines how UDINT, DINT, and REAL data from objects is converted into Modbus register data. The setting configures the order of the bytes for register values received or sent by a Modbus RTU Server or Modbus/TCP Server. Select the byte order and word order combination that matches the order expected by the Modbus RTU Client or Modbus/TCP Client that is polling the RTU. The order you select is used for 32-bit register values. ·2 bytes (1 word) are contained in the first register, and 2 bytes (1 word) are contained in the second	High byte/Low word first (3412) High byte/High word first (1234) Low byte/High word first (2143) Low byte/Low word first (4321)	The numbers 1, 2, 3, and 4 represent the 4 bytes in a 32-bit register value. ·High byte/Low word first o Sends 32-bit values in byte order 3412 o Default setting o Select this setting to emulate SCADAPack 300E RTUs ·High byte/High word first o Sends 32-bit values in byte order 1234 o Default setting if Realflo is enabled o Select this setting to emulate SCADAPack 32 and SCADAPack 300 RTUs ·Low byte/High word first o Sends 32-bit values in byte order 2143 ·Low byte/Low word first o Sends 32-bit values in byte order 4321
Swap Word Order for 32-bit Integers	Telepace firmware has a different word order for floats and long integers. A SCADAPack x70 device replacing a SCADAPack 3xx or 32 needs to behave in the same way. This setting defines if the 4 byte long integer data needs to be word swapped.This only happens for 32 bit long integer values, not for floats. For example, a configured byte order 1234 becomes 3412 for long integers only.	No Yes	·No o Long integers have the same byte order as floats o Default setting for newly created projects with Realflo disabled o Select this setting to emulate SCADAPack 32 and SCADAPack 300 RTUs with ISaGRAF firmware o Select this setting to emulate SCADAPack 300E RTUs ·Yes o Words for long integers are swapped o Default setting for newly created projects with Realflo enabled o Select this setting to emulate SCADAPack 32 and SCADAPack 300 RTUs with Telepace firmware

Released for:Schneider Electric India