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Yes, the Mirius will work for this application. I am the product specialist at ICC for the Mirius. You can email me directly (email is in my profile) or submit a support ticket on our website if you have additional questions on the Mirius or need assistance configuring the gateway. Details can...

This is a case of a misleading error message being returned. According to your attached packet captures, your master is sending the following request: 01 03 00 0B 00 01 F5 C8 - Device 1, Read Holding Registers, Register Address 11, Number of Registers 1 But your slave is responding with this...

Please provide more details on your issue. What are the master and slave devices you're using? How are you verifying the register values on the master and the slave device? Is the master showing an old/previous value for the register or is it a different value entirely? Please give an example...

I understand how industry conventions can evolve and deviate from specifications, so I can't argue that there are some implementations that exist that require other devices to be flexible in selecting different word ordering and byte ordering to be compatible. However, although they exist, I...

Very interesting, I've never actually thought of it this way. I've always just equated "data" to "register". So to take this a step further, does this mean that for a standard 16-bit Modbus register, it's possible that a client/master would need to byte-reverse the "register" value read from a...

Only one application can open a COM port at any time. This is why the COM port is not available in Modbus Poll when you have it open in LabView. There must be some other way to configure your serial interface without having to actively open the COM port in LabView. Google is your friend here...

If my previous assumption that Modbus Poll is receiving its own transmissions is correct, after you fix that, I suspect that you will see timeout errors in Modbus Poll because your PLC is not responding to Modbus Poll's requests. A timeout issue is almost always caused by either incorrect...

Your TX and RX packets are identical. It appears that your RS-485 adapter may be receiving its own transmissions. You can confirm this by disconnecting or powering off the PLC and see if you still receive the same errors in Modbus Poll. Assuming from your previous screenshot, you're using a NI...

Are you sure your PLC is configured as a Modbus slave and not a Modbus master? If your USB to RS-485 adapter has TX and RX LEDs or if the PLC has TX and RX LEDs, do any of these flash when Modbus Poll is not connected? If so, then your PLC is probably configured as a master too. Modbus Poll can...

Please tell us what is the Modbus device and what is the Modbus master you're using. If possible, include screenshots of your settings and the errors.

If you haven't looked at it already, take a look at the Modbus spec here (section 6.5 details Function Code 5 Write Single Coil): https://modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf From that section, "The Request PDU specifies the address of the coil to be forced."...

nikoloz, I'm happy to hear that you've gotten everything working with just a single "Refresh" button in your program and you now have a better understanding of the data conversion after viewing the raw bits of the registers. I've said it before, but it's worth stating again, the data encoding...

You're very welcome. I understand how development goes, and it certainly always helps to get a different viewpoint on things. I hope that my feedback and opinions are helpful. I wanted to add my thoughts on this for your consideration. This certainly is a good idea and would work, but is this...

I recommend you start by determining whether this is an issue with your Modbus client or the Modbus server. Try using a third-party Modbus client such as ModScan or Modbus Poll to read the register from the Modbus server. If you see the same behavior, then the issue is with the Modbus server...

I apologize, I still don't quite understand. From what I believe I understand, your Modbus device (which uses RModBus) is the client. Your client is reading/writing registers on a Modbus server device. The server has data registers, such as Charger Limit, that have a valid range of values that...

The onboard RS-485 port likely uses a proprietary protocol. The BMS board is a gateway device that translates between Modbus RTU and the proprietary protocol. Most likely, you'll need the BMS card to communicate to your A/C unit.

I understand. I just want to make sure you've considered the point I'm trying to make. If it is possible to have more than one sensor of the same type on the same network, how does the end user tell them apart? For example, if one sensor is giving an errant reading, how does the customer know...

Thank you for the details. So the sensor type is always unique? There's no scenario where two of the same sensor type would be installed on the same Modbus network? If that's the case, could you just enumerate all of the sensor types and each server's Modbus device address could be hard-coded...

Can you share the details of your application? I'm quite curious regarding what your devices are and what they do, since my colleagues and I cannot devise a real-world scenario where there would be no need to uniquely target individual devices. Along these lines, we did think of one scenario...

Is your Modbus device the client or the server? In your example, you state that the Charger Limit register value range is 0.0 to 0.0. Modbus itself doesn't define a value range for registers. Any range limitation is vendor-specific. Where does this range come from? What does "pass correct range...