A Modbus element which is read from a device has Signal field. SCADA-Communicator receives data from a device and retrieves an input channal number using Device number and Signal, then SCADA-Communicator passed data to SCADA-Server.
A Modbus element which is written to a device has Command number field. When you send a command, you use a specified output channel, so SCADA-Communicator chooses the appropriate command by Device number and Command number which are defined in the output channel.
KpSms.dll has no additional properties.
KpOpc.dll properies are specified for a device not for the whole library.
You don’t need to edit KpOPC_XXX.xml manually. Open the device properties from a popup menu by right clicking the device item of the tree. Device configuration form opens as shown in the article. If you open the configuration form you will easily understand the meaning of the XML.