The Allen-Bradley 1761-NET-DNI SLC 500 DeviceNet Interface Controller has three primary features: DeviceNet I/O, Explicit Messaging, and programing over the DeviceNet network.
The DNI is capable of being managed by a master on DeviceNet. This functionality on DeviceNet is part of the I/O class of services, and allows a master device to exclusively manage another device's (a different node number) data and resources. This type of relationship is functionally the same as a PLC with remote I/O. A PLC uses the remote I/O chassis as distributed inputs and outputs. The master/slave relationship on DeviceNet is exactly the same, except it is being done over DeviceNet.
The amount of data available between devices that implement I/O master/slave services is determined by the design of each device, and is not a function of DeviceNet.
The DNI on DeviceNet is capable of handling 32 I/O words of data with a DeviceNet I/O master for DNI Series A (64 for DNI Series B). This is broken up into two data images: the input image and the output image.
