Sending Control Commands to Samsung NASA via Modbus

[avishek]

Hi Team,

Good Day, trust you are doing good.

Please note that I am using a INMBSSAM016O000 Protocol Translator for Samsung NASA R1/R2 to Modbus converter respectively.

Initially, I got the scanning issue for which I raised a ticket and the issue got solved, based the instructions/suggestions given in the thread link below.

Cannot Scan Samsung NASA

Hi Team, Good day, trust you are doing good. I Have recently purchased the Protocol Translator INMBSSAM016O000 for Samsung NASA R1/R2 to Modbus from your institution. I have connected the R1/R2 wires as mentioned in the documentation, however, while scanning for Samsung Units it got the following error: “Unable to start the Samsung Scan process” [image] I have consulted your blog for further details, I noticed that the address should be set manually on the Outdoor Unit as per the link I…

Now I wanted to control the individual Indoor Units from Intesis software. I sent commands to the Intesis module via Modbus to switch on/off the indoor units using FC 6: Preset Single Register as shown in the picture below. Unfortunately, an am getting the following exception when sending commands to the VRV.

"Error: Modbus exception 2"

As you can see from the Intesis Slave Viewer, getting Err: 134 from Slv: 1

I don’t know what I have been missing out. Grateful if you could please extend your support.

Thanks for your help,
Best Regards,

[Kevin_hms]

Hello,

Modbus Exception Code 2 means the data address received in the query is not an allowable address for the slave. More specifically, the combination of reference number and transfer length is invalid.

The TX Error 134, means that the slave device is busy and try the command later.

From the error below, it looks like that address is Read Only.

Have you tried the same command on a different AC unit?

[Kevin_hms]

Hello,

Has there been any update on this issue?

[avishek]

@Kevin_hms

his issue?

Hi Kevin,

Greetings and Good day, trust you are doing and staying safe.

It’s been a while since I didn’t updated you on the progress for the Protocol Translator INMBSSAM016O000,

It’s mainly due to the extended confinement period here in our island, my apologies for that.

As mentioned earlier, the Scanning process got remedied, I can see 1-OU connected to 10 IU, thanks for your help.

However, now I noticed another issue while communicating from the Intesis MAPS software to control individual indoor units notably from the Diagnostic tab, whereby I manually entered logic [1] or [0] in the Modbus field to manage the IU as shown in the snapshot below, unfortunately, I am not able to do so, this is a real Catch-22 situation…

[VRV_working_18_may_2021.ibmaps|attachment]

You can refer to the snapshot below for reference, I have also attached the complete logs with debug enabled for both the Modbus Slave Viewer and Samsung NASA Viewer.

Can you please advise what is wrong with my current AirCon setup or any other problem related to it?.

VRV_working_18_may_2021.ibmaps (228.8 KB) modbus.txt (10.9 KB) Nasa.txt (97.4 KB)

[Kevin_hms]

Hello,

I am a little confused on what the issue is here. Are you trying to set the Modbus toggle in the Diagnostic tab? If so, if the field is grayed out, then you will not be able to due to the type of signal it is (read vs write).

As for the edit signals page, those are default signals that are not tied to any particualr Unit ID.

[avishek]

@Kevin_hms

the field is grayed out, then you will not be able to due to the type of signal it is (read vs write).

Hello Kevin,

Good day,

yes exactly I am also confused here, what I did is to make sure that the Intesis can control the IUs, I manually inserted the values in the Modbus field, in this case, it is either logic [1]/enable to activate or logic [0]/disable to de-activate you can refer to the below snapshot for the field/registers of interest.

I am getting the following errors

can you please advise that is the issue here??? in-fact I am trying to control the IU from Intesis MAPS software itself.

I don’t see what is wrong here?.so why I am not able to control the IUs from Intesis MAPs?.

thanks,
Best Regards,

[Kevin_hms]

Hello,

The signals highlighted in Beige do not have a Unit ID assigned. There for you are sending commands to an unknown desitnation. You either disable this signals in the Signal Tab, or assign a Unit ID to them.

You can verify this by toggling the signals that are not highlighted. They should have no errors when communicating with the Samsung device.