I'm starting a project to network into older Siemens equipment by serial port/protocol - specifically S5. Any suggestions of which protocol(s) will support the MOST old & new equipment. Multi-drop is NOT required - point-to-point is Ok. PC/DDE/OPC servers are irrelevant - I need to do the protocol work on a small embedded system to mount with the S5. I've heard of things like AS511 and R3946, but am not a Siemens expert & want feedback as to what are common older protocols. I repeat, the S7 are not in my scope yet - so PPI or MPI are not yet required. Thanks Lynn August Linse, Snr Prod App Engr Lantronix
The OPENJTAG PROJECT protocol is simple and easy to understand. Only one or two bytes are needed to make a complex operation, like move the target TAP state machine, shift a byte, etc.