Enet switch: N-tron, Hirschman, or Phoenix?

[jstolaruk]

Another small comment. This appears to be a case of re-inventing the wheel. There has been a perfectly useful and functional deterministic network out there for about as long as I have been playing with computers. It is called Token Ring.

My favourite peer to peer PLC network is token ring based. It only runs up to 750kBaud on a twisted pair but is perfectly reliable. One system I installed some years ago has about 3000 words flying around the network between PLCs (9 of them) and Citect SCADA system hammering on the network also. Citect reports in excess of 11,000 digital reads per second and over 100 word reads per second. This is in addition to the other network traffic between PLCs.

The scan time for the network averages 20ms. Imagine what the network could do if they speeded the thing up to 100mb!!!!

I am not an IT person and therefore have no real idea of the logistics and performance capabilities of both networks. I only judge by what I see and experience. Perhaps someone here a lot smarter than me can explain why Token Ring appears to be so much better than Ethernet to me and why Ethernet is now being made deterministic when there is what appears to be a perfectly good network out there that would save having to re-invent the wheel.

Is it a similar case to VHS vs Beta? Marketing blurb, price, etc and then try to fix it later? Am I way out of court here? Look forward to some comments on deterministic Token Ring vs Ethernet that is now being made deterministic from someone versed in IT things. I wish to learn more about both networks if possible.

Token ring was an IBM invention and just like the PS2 line of PCs and OS/2, it suffered from a poorly managed sales effort.