For point-to-point communication, the SNPX protocol is 5 to 10 percent faster than SNP protocol if the average packet size is greater than 100 bytes. The difference becomes smaller when the average packet size get bigger.
The SNPX protocol is 5 or even 10 times faster than the SNP protocol in multi-drop communications.
In multi-drop communications, the
SNPX protocol supports broadcast-attach which makes the SNPX device
communications option attach to all the PLCs at the same time.
After attaching to all the PLCs, the SNPX device communications
option can send a request to any PLC in the network without
re-attaching to it.
Currently, it takes approximately
0.6 second for the SNP communications option to attach to a PLC
each time the communications option sends a data request.
About SNP and SNPX Communications. |