data transfer rate between PLC and HMI

Hi ALL

What will be the data transfer rate between AB PLC and AB Panel view.

Will it be depend upon the processor speed.


Thanks in advance for your valuable answers.

MJK

Which AB PLC?
Which AB PanelView?
Which communincations Protocol?

The type of communications used will have the biggest impact.

Another would be if you've optimized the addressing in such a manner that packs it all together. Addressing that is all over the place in the PLC is less efficient then addresses that are compacted together in arrays.

AB SLC500, Panel View 1000 plus
and Ethernet communication

Still unanswerable. How many tags on update? How many alarms?

In general, the update rate will be whatever you select on the display properties page, if it can be achieved.

How fast do you actually need? Anything faster then 0.5 or 0.25 second update rate is overkill. If you are trying to catch transient events, it's not going to happen.

Generally in communications the poll cylcle is the time it takes to read all data on a single communicaitons thread (comm port or TCP/IP/UDP Socket) once. With serial connections you have to factor how many bytes in each request and response pair with the time it takes on the wire to transfer each byte of that pair, plus the time it takes for the PLC to turn that request around. At 9600 baud it takes about 1 msec to transfer 1 byte so a 10 byte request and a 60 byte responses wiht a 30msec turn around time would be 100msec.

Wiht Ethernet the wire time is essentially eliminated. This is because the PLC Manufacurers have typically kept the packet sizes small. The poll cycle in ethernet is now cacluated by the turn around time multipled by the number of packets. Oh, and did I mention that the runaround time can vary from one request to the other.

My sugguestion for Ethernet based connections is to use a product like Wireshark to sniff the communications between the panel and the plc. We use it all the time when looking at customer issues.

Rockwell has an Ethernet Traffic tool

http://www.rockwellautomation.com/solutions/integratedarchitecture/resources3.html

It's not 100% accurate but it will give you an idea.