Modbus/TCP 7-7
© 2005 HMS Industrial Networks
AB7607 User manual
I/O Data Format
The Anybus-X transfers I/O data between Modbus/TCP and DeviceNet without
regard to data content or format. Due to this, the user is responsible for making
sure that the devices on either network understand the format of the data.
DeviceNet is a little endian protocol; values are transmitted least significant byte
first. Hence, all data in the I/O tables is assumed, by the DeviceNet nodes, to be
stored as little endian.
Care should be taken to make sure that the Modbus/TCP master handles input data
and transmits output data in a format acceptable to the target DeviceNet devices
(least significant byte first).
The I/O Byte Swap option will aid this issue by swapping the bytes on 16-bit
boundaries. However, the user is still responsible for knowing where in the I/O
tables DeviceNet data has been mapped.