Emerson Exchange 365

Connecting two 1420 WirelessHART Gateways on the same fiber backhaul to the DeltaV Primary / Secondary network

I am adding another WIHART gateway (1420) in an area of the plant where I already have one close by . . . so there's a single fiber pair going there from the DeltaV network for connecting the original to the DeltaV Primary / Secondary network.

Rather than install more media converters and consume more ports of our DeltaV switches, I want to install a simple hazardous-area capable switch like this out in the field. As I am using this mainly to allow management of the 1420's through AMS, is their any grave sin in creating a "forked spur" if you will, connecting back to DeltaV? All the wireless I/O will be coming in via Modbus (as is the case with the existing one).

I know DeltaV is fastidious about having a pure "star" network - what do I risk by expanding the network in this way?

Thanks,

John

• 1420
• DeltaV Network

John Rezabek

• 7 Oct 2016 4:24 PM
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5 Replies

• Alexandre Peixoto

  

  • 7 Oct 2016 5:03 PM

  John,
  
  if you'd rather use switches in the remote end where the 1420 Gateways are located to establish these connections instead of media converters, then I'd highly recommend using one of the supported switches we have on our portfolio, either the unmanaged ones (the VE6019 has fiber and copper ports), or pick one of the FP20-Series DeltaV Smart Switches (the VE6041 also has options with fiber and copper). These switches are tested with DeltaV systems and have options to be deployed in hazardous areas. The "forked spur" concern is not an issue in your specific use case (it actually is documented in many of our design documents where DeltaV Smart Switches are interconnected to build that kind of topology for DeltaV embedded nodes).
  
  If I'm following you correctly, you have one fiber-pair for each one of the DeltaV network segments (one for primary and one for secondary), and there may be special reasons for using Modbus as your wireless I/O integration, but I thought it'd be good to comment add a comment about this wireless I/O integration which could also be helpful on your application since the 1420 Gateway is already connected to the DeltaV ACN. You could make good use of the wireless I/O integration via the native DeltaV Ready feature available for 1420 Gateways. This native integration requires DeltaV v10.3 or higher, and must also be enabled within the 1420 Gateway itself.
  
  We can discuss additional details about your topology, as I'm specially interested on the Modbus integration you are currently using, but I hope this original thought could be of help.
  
  Cheers,
  
  Peixe

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• Andre Dicaire

  

  • 7 Oct 2016 6:48 PM

  John, Are you actually connected to the DeltaV Network with the Modbus Protocol? If so, that is not supported, and the use of a switch is the least of your concerns... If you are connected to the DeltaV network, you must use the DeltaV Ready Protocol and integrate the Gateway as an Wireless IO node.
  
  The gateway is a standalone wirelessHART interface and supports HART over IP, which AMS Device Manager uses. MODBUS TCP is provided to integrate data to any system. It also supports an OPC Server. One port would typically connect to a host system and the other would be used by AMS Device Manager or other diagnostic software. The DeltaV ready protocol allows both Ethernet Ports to be used for redundant communication back to a DeltaV Controller, and also connects the gateway to AMS Device Manager through DeltaV's pass through mechanism for HART.
  
  If you are actually using Modbus TCP, then you should be connected to a VIM and this should be a separate network from DeltaV, and that means DeltaV network rules don't apply. You can use any switch you like.
  
  If you are using DeltaV Ready, then you are connected to DeltaV. You can use a switch. If you are using Multi Mode fiber, the VE6019 mentioned by Alex is a good choice. This is an unmanaged switch rated for hazardous areas. If you are using Single Mode fiber, the VE2019 will not work. The VE6041 Smart Switches can be ordered with Single Mode uplink ports, but are much more expensive and likely overkill for what you are describing. Hirschman make the Spider line of small unmanaged switches/media converters that also could work. These are listed in the Alliance Program with Emerson.
  
  I looked up the model you linked to. I would not recommend these on the DeltaV network. They have some management settings and might have "Features" to help you, that in fact interfere with how DeltaV uses various features of the Ethernet layer. If you are on a separate VIM network, with MODBUS TCP, it will not matter. But if you are on a DeltaV network, you should only use Smart Switches or unmanaged switches.

  Andre Dicaire

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• John Rezabek

  

  • 7 Oct 2016 7:16 PM

  Gents,
  
  Thanks for the quick and thorough advice. I am using "DeltaV Ready" 1420's and they do want to map as wireless IO nodes. I started using Modbus RS485 (serial) back to a DeltaV serial IO port initially for expedience - twisted pair and existing RS485 Modbus were already in the vicinity. So no I am not using the Ethernet for Modbus TCP. I have experimented with the wireless IO which does offer some good features, however I noticed it was consuming one DST per point, and the original project didn't have funding for adding more DST's.
  
  Our site does utilize the RM|00 "smart" switches - if I can convert one of the ports to fiber, the VE6019 looks like the ideal solution.

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• Andre Dicaire

  

  • 7 Oct 2016 7:21 PM

  In reply to John Rezabek:

  As long as you have Multi Mode fiber installed, that is the way to go.

  Andre Dicaire

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• Alexandre Peixoto

  

  • 7 Oct 2016 8:09 PM

  In reply to John Rezabek:

  John, if the RM100-Series has two built-in combo ports (copper/SFP) that you could use if they are still available in your case. If you have a modular RM100 (VE6048 8-ports with slots dor additional two 8-ports modules) then you could add fiber modulea which can be multi-mode as well.
  
  It seems you have a couple of options to choose from. If you need additional info about these switches you can find on the DeltaV Smart Switches, and the Deltav Control Network Hardware product data sheets.
  
  I'm glad this helped you!
  
  Regards,
  
  Peixe

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