Which network permits all nodes on the network to simultaneously access the same data from a single source?

• A. ControlNet
• B. DeviceNet
• C. FOUNDATION Fieldbus
• D. SERCOS

Answer: (A)

The situation tests how data is shared across nodes in a real-time network: one source produces data and all other nodes access that same data in a way that’s effectively simultaneous. ControlNet is built around a producer/consumer model with a deterministic schedule, so a single data item from one source can be distributed to many consumers across the network in the same cycle. That makes every node see the same value from that single source at roughly the same time, which is exactly what this item describes.

Other networks use different data-distribution approaches. Some are primarily master/slave or point-to-point in nature, or they rely on distributed control models that don’t guarantee that all nodes read the same data from a single source at the same moment. Foundation Fieldbus, for example, supports shared data in a distributed fashion, but ControlNet’s architecture is the clearest fit for one source driving multiple nodes with synchronized access.