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Author Topic: Broadcast Messaging  (Read 10936 times)

RBPLC

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Broadcast Messaging
« on: October 28, 2019, 10:05:05 AM »
I may have missed this, but does DMD have its own broadcast messaging capabilities? What I mean by this is, does DMD have something similar to ProNET in the Productivity controller? This would allow a DMD device with an ID number to broadcast an array of data on the network and another DMD device to pick up that array by listening, for example, to Device 1. I realize this can be done with Modbus and EIP, I just didn't know if there was a "DMDNet" equivalent to ProNET.

franji1

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Re: Broadcast Messaging
« Reply #1 on: October 28, 2019, 11:09:44 AM »
Yes, PEERLINK.  This is global data across all your Do-more PLCs.

There is a data block 256 WORDs of 16 PEERLINK "blocks" 16 WORDs each.  So PEERLINK Block 0 is PL0-PL15.  PEERLINK Block1 is PL16-PL31.  ? PEERLINK Block15 is PL240-PL255.

Each PLC can publish 0 to 16 blocks.  All PLCs can subscribe.  If you have 16 PLCs, they could each publish to a different PEERLINK block, and all 16 PLCs would have all the data from those 16 PLCs.  You could actually have 1000 PLCs that are subscribers only, and those 1000 PLCs would have their PL block be updated.

Look at the PEERLINK instruction.  Help topic DmD0300.

It just works

franji1

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Re: Broadcast Messaging
« Reply #2 on: October 28, 2019, 11:11:35 AM »
Look at CASTING if you need to publish bits or REALs.  e.g. PL0:0 is bit 0 of WORD PL0.  PL0:15 is the MSBit of WORD PL0.  PL0:R is a 32 bit floating point number of PL0/PL1

RBPLC

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Re: Broadcast Messaging
« Reply #3 on: October 28, 2019, 11:29:44 AM »
Thanks franji. I was looking for a specific setup option in the configuration menu and couldn't find it, but apparently no additional configuration is needed. So the way I read it, to subscribe, all you have to do is put PEERLINK (nothing checked) on a rung and it will be subscribed to all PEERLINK published messages? 

franji1

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Re: Broadcast Messaging
« Reply #4 on: October 28, 2019, 01:35:25 PM »
Thanks franji. I was looking for a specific setup option in the configuration menu and couldn't find it, but apparently no additional configuration is needed. So the way I read it, to subscribe, all you have to do is put PEERLINK (nothing checked) on a rung and it will be subscribed to all PEERLINK published messages?

Correct.  Also, PEERLINK must be in $Main.

franji1

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Re: Broadcast Messaging
« Reply #5 on: October 28, 2019, 01:41:43 PM »
Oh, and I hope you like the status.  We worked on that a while.  The Help topic goes into some detail (see attachment).  All of that information is available in the PL heap-item (e.g. PL.B0Rate is the # of transfers in the last second for Block0)

RBPLC

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Re: Broadcast Messaging
« Reply #6 on: October 28, 2019, 02:53:04 PM »
Can PEERLINK be used on both the primary Ethernet network and the secondary network (if using a POM module)?

franji1

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Re: Broadcast Messaging
« Reply #7 on: October 28, 2019, 03:05:52 PM »
No.  Only the main Ethernet port on BRX.

The H2-ECOM100 supports Peerlink protocol, with some setup (in the H2-ECOM100 module, not in Do-more project).  It even works with DL CPUs (like 260), in addition to Do-more.  Hence, you could have multiple Peerlink networks with 205.