Note: The information in this help topic applies when exchanging longs and/or floats among SIXNET stations configured to respond to Modbus protocol. Other Modbus compatible equipment may be addressed differently.
The standard Modicon protocol supports the transfer of each floating point or long integer value as a pair of consecutive 16-bit analog registers. Some SIXNET stations can be configured with I/O transfers to read / write longs and floats.
In the station’s I/O transfer definition, specify the "First Register Number" of the remote station as an odd-numbered Modbus address or as an even-numbered SIXNET equivalent address. (Each even-numbered Modbus register contains the second half of the 32-bit value.) Refer to the Modbus Addressing Versus SIXNET Addressing topic for Modbus addressing information.
Here are some Modbus address examples. The first digit is the type number. The last 4 digits are the address. Note that a colon separator has been placed between the type number and the address for visual purposes only. Do not include the colon when entering a Modbus address.
3:5001 = Long input 0 of the station 4:5001 = Long output 0 of the station
3:5003 = Long input 1 of the station 4:5003 = Long output 1 of the station
3:5007 = Long input 3 of the station 4:5007 = Long output 3 of the station
3:7001 = Floating input 0 of the station 4:7001 = Floating output 0 of the station
3:7003 = Floating input 1 of the station 4:7003 = Floating output 1 of the station
3:7007 = Floating input 3 of the station 4:7007 = Floating output 3 of the station