TI505 TiWay vs. Peerlink

Can anyone briefly describe the difference in/between the TiWay and Peerlink networks.

I have inherited some old TI505 control systems that employ both "networks" simultaneously. With no documentation (yet found) and very little physical site investigation (so far), I'm hoping someone can give me a primer on the applications or differences or why both are required.

TIA...Von

Goto: http://www2.sea.siemens.com/Products/Automation/Programmable-Controllers/Programmable-Controllers-SIMATIC-505-Manuals

A rather simple explanation is TiWay connects a PC for SCADA or programming to multiple TI500/505 PLC's. Peerlink connects multiple TI500/505 PLC's for data exchange.
I haven't used TiWay but had one system with a TI545 and TI525 Peerlinked for data exchange. The Genesis MMI was connected to the TI545 via serial port. The comunication was quite reliable.
I'm sure the more experienced guys out there can give you more in depth information.

Just as the man said.

Tiway was a hosted system, (host = PC or equivalent) and all the PLCs were 'secondaries' on the network. They could never initiate comms and only responded to message or requests from the host. Data exchange between PLCs was only possible by the host reading from one and writing to the other. If the host died all network traffic stopped.

Peerlink was a subset of Tiway using same electrical specs and cabling. No external host - each PLC was its own 'host'. Here up to 16 PLCs could be connected together in a token-passing system. Each one took it in turns to broadcast a small set of data (16 words max.) to all the others on the network. If one or more PLCs died every one else just carried on until there was only one left. Cut the cable, and then you could have two seperate networks chugging away! Very easy to set up and very resilient.

regards

Ken

Thanks Folks!

Von