In addition to the technical definition, determinism was the marketing term by those selling networks competing with Ethernet. Ethernet is not deterministic. There are some excellent network communications tutorials on the web that include Ethernet, ArcNet, and other techniques. I am not at my base where these may be saved in favorites. With a deterministic network the message is sent and the receiver acknowledges receipt. Ethernet is subject to data collisions, etc. However, the present Ethernet speed and available accessories such as switches and routers permit fast and reliable data communications.
Determinism is the ability to respond in a consistent, predictable time delay. Ethernet, even if it can be a fast network, is not determinism as collision between messages can create unpredictable delay. Of course, if the load on the network is very low or if you use Ethernet switch, it is possible to considerate Ethernet as determinism for slow to mid speed system. Some other network technology was developed specifically for process control and they are really determinism. Don't be mix-up by marketing: determinism just mean that the delay are consistent and predictable, but give you any information relative to the speed of the network.
