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  • Hi all, I am trying to configure a BARIX R6 Modbus relay board. I have created the data source but am now unsure about how to write to the points. I intend to use this module to control loads with the relays.
    The following is the register map:

    Detailed “register” map – again – please note that the protocol address in Modbus/RTU is the register number -1 !!
    Registe r
    1 Live I/O (Byte, Relay state in bit 0..5)
    2..256 Reserved, not accessible
    257 Device type (hex 0xB1)
    258 Firmware version
    259 Serial number 1st part
    260 Serial number 2nd part
    261..264 reserved
    265..272 One-time writable for installer
    273 Default relay setting for startup
    274 Serial interface mode
    275 Modbus address
    276..289 reserved
    290..512 Memory for installer/software use
    513.... 65536

    Any help is greatly appreciated.

  • Hi Chromeaccent,

    My first step was googling for a manual. I found this: so I will be presuming you're talking about that device.

    The "Supported standard commands" indicates that only read requests on holding registers are supported, so I am guessing those values in your post are holding register offsets. The bit about "please not the protocol address in..." is informing us that it is a 0 offset implementation, but that it's presenting information with a 1 offset. So, in using the test tools, I would assume reading Holding Register 256 should give you the Device Type

    I do not see the slave ID for the device described in the document, but they say that there is a jumper that can force it into default settings (although it appears from the document that the default modbus address is 255, which is frowned upon in the Modbus spec and you may have issues. I may be able to supply you with a sly workaround to set a better slave ID if this is an issue, but perhaps you have the tools to set the PLC's slave ID or you know it has one that is lower than 247, and this won't be an issue)


    A request that i think should get the Device Type

    Settings in document: 19200 baud (bit rate), even parity, 1 stop bit. This would be a Modbus Serial data source.


  • It looks like for Write commands you will be writing to Coil Status registers 1-6 (0-5?), once you have communication going.

  • Thanks for your quick response. I have been trying to use Modbus poll from Modbus tools as a master in order to change the R6 address, however, I have been having communication issues with it. I will try the setting listed above and let you know.

  • When I attempt to write to the device I keep getting:
    There was a problem testing the locator. ( Port /dev/rs485-1 in use by Mango Modbus Data Source DS_451699)
    Any ideas?

  • You need to disable any data sources using that port before using the test tools. I'm guessing that is the issue.

  • Hi Chromeaccent,

    It is possible the parity is "None" instead of "Even" as the manual is not clear. "Even" is the default but "None" is also listed as a supported possibility. From the document:

    Supported interface configurations are
    19200 baud, 8bit, even parity, 1 stop bit (**default**)
    19200 baud, 8bit, no parity, 1 stop bit
    9600 baud, 8bit, even parity, 1 stop bit
    9600 baud, 8bit, no parity, 1 stop bit

  • Hi Phildunlap,

    I was able to get another Modbus device display, this device has two data points, temperature and relative humidity, however, I am at a loss as the Barix R6's configuration. Strangely it responds to Modbus poll.
    By the way, I have not seen Relative Humidity(RH) in the point properties drop down menu.

  • I don't know what you mean, "Strangely it responds to Modbus poll" You are not using Slave Id 255 are you? I would not expect that to work. It must have a slave ID <= 247

    If you are not seeing the Units (I assume you are referring to units) you need, you can set a custom suffix in the text renderer section of the data point.

  • I did change the address to 200 for the R6, I also had to change the address for the other device, this I changed to 230. One thing I did notice was that at first, I would get the result for temperature in Hexidecimal but after a while it changed to decimal values.

  • Can I use a crossover cable to connect my mango ES to my laptop?

  • Ethernet? I suspect so, but I've only used a standard ethernet cable for that purpose (haven't ports been self detecting and switching for a half decade or so? ). Then you'll probably have to give your ethernet interface a static ip on the same network or listen for its IPv6 address and use that.