The EDS file may contain information about the data length, but it does not contain any information about the data itself. The user maps the data to signals which have no semantic meaning to the system. For each signal you can specify signal direction, data type, byte offset, scaling, and the bit pattern.
You can configure a device's signals at the DeltaV Explorer library level and at the physical network (I/O) level.
Library Configuration - To save engineering time for similar devices, create default signals in the library. Configure the signals that are common to all the instances of the device. When the default information is complete, drag the device revision to a DeviceNet port on the network.
Physical Network Configuration - Select the device at the I/O level, select New DeviceNet Signal from the context menu, configure the signal, and then assign a Device Signal Tag (DST) to the signal. (Select the signal, and then select Assign Device Tag from the context menu.)