Start by creating an Ethernet network in Unity. Go to Communication > Networks, Right click and choose New Network.
Choose Ethernet and name the network.



Next configure the network as needed for your application. Be sure to choose the correct Model Family for the Ethernet interface you will be using.
Don't forget to validate your changes.



Next link the network to the Ethernet port of your module by double clicking on the port in the configuration and then choosing the network name.
Once again don't forget to validate your changes.





Open the Variable Declaration and create the following variables.
Note: The WR_Data & Slave_Addr variables are located.



The WR_Data variable is the memory location to where the data being written to the slave will be stored in the master Quantum PLC.
The Slave_Addr variable is an Array of 5 words where the high byte of the first word is the physical slot that the Ethernet module is in the backplane and the low byte is modbus mapping index.
The remaining 4 words are the IP address of the slave device. In this case 192.168.40.7
Note: If using the embedded port of a Unity Quantum the high byte of the first word should be FE

Next create a new project section, choose a language, and name the section.



In this section add a WRITE_REG block and link the variables as shown.



The SLAVEREG pin is the starting address in the Slave device where the data will be written to. In this case %MW1510.
The NO_REG pin is the # of registers to be written.
Note: If writing more than 1 register then the WR_Data variable must be an located Array of INT with a length equal to the # of registers to be written.

Build, download and run the program.