adccommunitymod (AutomationDirect) asked a question.
Created Date: April 24,2018
Created By: bsinkovich
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I am working on a new project and don't have p2ks laying around. I was reading up on p to p communication using pronet. Using the software I see where the pronet is set up in the hardware confg. In the help screen it states : "When the input logic to the ProNET configuration is Enabled, at a fixed rate of 10 times per second (100 msec.) " Where is this 10 times per second set up at? Or is this rate fixed into the plc? If this is the case, I would need no latter logic to send or receive, just some array manipulation for the incoming and out going data? Any way to change the timing faster?
Created Date: April 24,2018
Created by: bsinkovich
I am working on a new project and don't have p2ks laying around. I was reading up on p to p communication using pronet. Using the software I see where the pronet is set up in the hardware confg. In the help screen it states :
"When the input logic to the ProNET configuration is Enabled, at a fixed rate of 10 times per second (100 msec.) "
Where is this 10 times per second set up at? Or is this rate fixed into the plc? If this is the case, I would need no latter logic to send or receive, just some array manipulation for the incoming and out going data? Any way to change the timing faster?
Created Date: April 24,2018
Created by: bcarlton
It seems very similar to the Peerlink setup in the DL/ECOM and the Do-more systems. If so it's fixed at that rate. You might be able to get faster response with Modbus or Network Read/Write chains of instructions. It appears that the Pronet (just as Peerlink) is for ease of setup rather than speed.
Created Date: April 24,2018
Created by: MikeN
If you use a second P2k with a Remote Slave CPU, doesnt it also not require any special logic, ie. it "just works ", once you get your address set? I havent looked at it in a long time, but from what I remember it updates the remote slave every scan too, which should be way faster than ProNet. Might be a better choice if both p2k's are working together to run a machine.
Created Date: April 25,2018
Created by: techme
Where is this 10 times per second set up at?
This is a fixed rate that is not user adjustable.
If this is the case, I would need no latter logic to send or receive, just some array manipulation for the incoming and out going data? Any way to change the timing faster?
There is an ENABLE tag used for the publisher and subscriber device configuration. That bit can be manipulated in ladder or a tag such as "CPU In Run " bit can be used so it publishes/subscribes anytime the plc is running.
Created Date: April 25,2018
Created by: bsinkovich
Thank for all the replies. I want to run a master controller plc and have 3 or 4 other controllers run specific tasks for the machine. I dont think communication speed will be a problem, most time critical running in in the plcs running those specific tasks. Just wanted to hedge my bets. See other post on question on following/gearing.
Created Date: April 25,2018
Created by: bsinkovich
One more question, Does the rate double triple etc with more p2k on the line?
Created Date: April 25,2018
Created by: MikeN
One more question, Does the rate double triple etc with more p2k on the line?
If you use a main p2k and a bunch of remote slave units, you can have up to 8 slaves. Each scan it will update one slave, then move to update the next slave on the next scan. Most of my programs have scan times around 4-6 milliseconds. So with 4 slavces using a master CPU and a bunch of RS CPUs, it could take up to 24ms to come around to updating a slave again.
I am not sure exactly how ProNet works. It may be that with ProNet you could simply publish tag info across the nextwork and all subscribers that are looking for that tag would be updated? If that is the case, then ProNet may be faster in the end with 3-4 other slaves since a 10ms interval to update them all would be faster than the 10-20ms it would take to go through each slave in order updating each one at a time through the RS CPU method.
Created Date: April 25,2018
Created by: techme
One more question, Does the rate double triple etc with more p2k on the line?
Depends on if you make them all publishers. It is network traffic. But it will not exponentially increase the rate for the publish devices if you have multiple.