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  1. #1

    WebCtrl - modbus embedded in a bacnet device, trying to read from a 3rd party program

    I am attempting to integrate with a power quality meter that is being pulled using WebCtrl.

    When I go into the watts object in WebCtrl the address is listed as modbus1://UINT/289/6

    When I go up a level to the device I see Device: Device: 05 LGR1000 PQM-EPM Meters ( device_05 ) Address: 2412 : 05 on the Media: 2412 Arcnet network

    The level above that has: Reference Name: device_05 Display Name: Device: 05 LGR1000 PQM-EPM Meters
    Device Definition Name: LGR1000 Access Type: mpx1
    Database Driver: drv_melgr_mb_multi_2-18a-002
    Device Instance: 241205 Address : 05


    To me it looks like I have a modbus point embedded in a BACnet device.

    I'm trying to understand how to poll that point using a 3rd party optimization tool for the facility. The tool can use BACnet or be a modbus master.

    Any suggestions would be most hopeful.

  2. #2
    Join Date
    Jul 2006
    Location
    Southern California
    Posts
    230
    Did you get your information above using a "BACnetIP" data sniffing program?

    It would appear that the points you are looking to "poll" are inside of an ALC LGR 1000 router and
    depending on how the Modbus program was created, the points for the power meter may be BACnet/IP discoverable.

    ALC WebCTRL and Carrier i-Vu both allow for bringing Modbus data points into their BACnet controls thru many
    different configurations.

    Depending on the "electronic" technology (EIA485 or TCP/IP, or Modbus485), and software topology and protocol
    (BACnetIP, or BACnet MSTP, or ModbusIP, or Modbus IP) there are many different ways to poll these points,
    if the ALC programmer made them accessable to the different BAS network(s).

    If you could please describe which forms of technology you plan to use to integrate,
    I could provide some clarity to you case.

    BACnetIP is the fastest, and most reliable, with the least potential for technology configuration issues,
    but you will need to be IP savy. Contact the site owner's ALC top guru, and ask them to check to see
    if the Modbus points are available as BACnet points, and if not, what it would take to modify the
    program to make them BACnet visiable.

    All of the above is relating to just "reading the modbus data points", and doesn't address "writing to anything",
    which is another very large can of worms if you are struggling with this level of integration.

    Anyway, hope this aims you in the right direction.

    (PS: the configurations for the Modbus points you noted, are not "ModbusIP points",
    and are likely Modbus 485 or Modbus RTU wired to one of the comm port's on the ALC LGR1000)
    "We are what we repeatedly do. Excellence, then, is not an act, but a habit" Aristotle

    Remember to "Pay it Forward"; help out the newer generation of techs, remember someone during our career helped us! ("Pay it Forward" was by someone smarter than me!!)

  3. #3
    I was digging through the network tree in the WebCtrl for the site. It looks like there is a meter on a serial connection to the LGR, then an arcnet connection to another LGR which then is integrated into the BMS using BACnetIP.

    There doesn't seem to be a way to address the point on the meter I'm after from an external device; I think they're going to have to map it to a device I can directly poll.

    The rest of my integration went just fine and was a combination of BACnet IP and Modbus TCP, depending on the end device. The UPS system was BACnet and the other power meters were Modbus TCP.

    The system/tool that is integrating to WebCtrl is a proprietary product and is somewhat rigid in structure and does not allow for customization and the polling of an object structured like this; modbus nested in bacnet.

  4. #4
    Join Date
    Jul 2006
    Location
    Southern California
    Posts
    230
    Cool, sounds link you are having fun. Smells data center "ish".

    There are some great free BACnetIP and Modbus TCP sniffing programs out on the WWW.

    It would be very cost effective and easy to modify the existing LGR1000
    modbus program in Eikon or Logic Builder to make those points available to you
    BACnet/IP. Of course depending on the ALC programmer you use.
    If you are not an ALC dealer, and they see you as a threat, there is a potential for the programming cost
    to be higher than normal.

    Anyway good luck.
    "We are what we repeatedly do. Excellence, then, is not an act, but a habit" Aristotle

    Remember to "Pay it Forward"; help out the newer generation of techs, remember someone during our career helped us! ("Pay it Forward" was by someone smarter than me!!)

  5. #5
    Dracula,

    Yes, it is indeed a datacenter. The BMS integration is a bit new to me and I have to be somewhat vague because of not being able to disclose client and site information.
    Most of my previous experience has been in the power plant world using modbus, dnp3, and iec61850.

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