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Author Topic: Fastest method for multiple PLCs to transfer data  (Read 13327 times)

MarkTTU

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Fastest method for multiple PLCs to transfer data
« on: May 27, 2010, 10:34:19 AM »
If I have six machines on a network each with their own PLC (DL06) and ECOM100 and a single PLC (DL260) with an ECOM100 that collects data from each machine would it be faster for the six DL06s to send data to the single DL260 or for the single DL260 to pull data from the six DL06s?

My initial thought was to have the DL260 pull data from the DL06s, but since I can only execute a single RX command each scan I am at the mercy of the DL260's scan time (approx 200ms). That means to get data from each DL06 I have to wait 1200ms which is an eternity...

Reading this FAQ (http://www.hosteng.com/FAQFiles/ECOM.htm#FAQ0014) I get the impression that the DL06 and DL260 are both capable of processing 3 comms per scan. Since I can only initiate a single comm per scan on any CPU (ladder is only going to execute once per scan) does that mean it would be faster for the six DL06s to each have a WX command sending data to the DL260? In that way could the time I wait for all the data to arrive be cut to 400ms?

I've also posted this question over at AutomationDirect (http://forum.automationdirect.com/showthread.php?p=33556#post33556).
« Last Edit: May 27, 2010, 10:39:09 AM by marksji »

franji1

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Re: Fastest method for multiple PLCs to transfer data
« Reply #1 on: May 27, 2010, 10:57:22 AM »
Yes, your analysis is right.  The overall throughput would be better with the "slaves" "pushing" their data to the "master".  Isn't peer-to-peer wunderful!!  ;D

MarkTTU

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Re: Fastest method for multiple PLCs to transfer data
« Reply #2 on: May 27, 2010, 12:01:36 PM »
Thanks Franji!

Controls Guy

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Re: Fastest method for multiple PLCs to transfer data
« Reply #3 on: May 27, 2010, 02:11:18 PM »
Yes, your analysis is right.  The overall throughput would be better with the "slaves" "pushing" their data to the "master".  Isn't peer-to-peer wunderful!! 
Good to know.  Thank, Mark.
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