Once the physical and logical network set-up is complete, it is time to implement the server side of the FANDA communications. Add one or more global variables to a schema as in Figure 9.146.
Figure 9.146. Pressure, Temp and Status are all Global Variables
Right click on the module on which the schema is executing and select Global Variable Settings.
There are two fields in the resulting table (Figure 9.147) relevant to FANDA set-up, Network Access and Multicast.
Figure 9.147. Global Variable Settings
Network Access allows specification of whether the named variable may be read by, written to or both by the FANDA client(s). Multicast determines whether the variable value is made available to clients listening to an Ethernet port specifically used for FANDA communication.
Make the appropriate changes to the table. Save the Global Variable Settings by pressing OK and set-up is complete for communication with a FANDA client.