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by anonymous
Hi,

I am using 2-wire RS485 to transmit the sampled data to TRB 245. Could anyone please tell me:

where the transmitted data is stored in the TRB 245?

Is it stored in a specific register, or somewhere else? How can I access to the place where it is stored?

Kind regards

Z WH

1 Answer

0 votes
by anonymous

Hello,

 

Is not possible to store MODBUS data, but you can send data to an external server using the Data to Server feature. You can read more about this at this Teltonika Networks Wiki link: https://wiki.teltonika-networks.com/view/TRB245_Data_to_Server

by anonymous
Hello,

Thank you very much for your reply.

If I use the Data to server function to transmit data, I need to configure the MODBUS. In either the modbus master or modbus serial master, I need to add a slave. In modbus slave, I need to add an instance from which the data will be transmitted by trb 245. In the request configuration, there is an option to select the first register.

From my understanding, the data is read from the first register and the following register.

Therefore, I would like to ask if I want to transmit the data which is sampled by an external device and transmitted to trb 245 via rs-485, which register number should I write to the request configuration part.

I would be appreciated, if you can give some advice or answer to this question.

Kind regards

Z WH
by anonymous

Hello, 

For reading information of a device you need to install a Package on the Package installer called Modbus Serial Master. After that please configure the slave device and the MODBUS request, this is where you have to configure the registries, but the registry needed for reading specific data depends on the slave device. 

Another thing, once you installed the Modbus Serial Master package there will be a place where the data collected is going to be stored, you can find this data on the next linux directory /tmp/modbus_db. To get this information you have to connect through SSH to the device.

You can read more information about the Modbus Serial Master Service at this Teltonika Networks Wiki link: https://wiki.teltonika-networks.com/view/TRB245_Modbus#Modbus_Serial_Master

Hope this helps, if it doesn't please leave another comment.

by anonymous

Hello

Thank you very much for your comments!

I have installed the Modbus Serial Master. I am not really understanding why the registry needed for reading specific data depends on the slave device. I was assuming the data was stored in a constant registry inside of TRB245. If it is not true, please tell me the right answer.

I have connected the TRB245 via SSH (by PUTTY). The user name I used is root, but the access to the repository /tmp is denied. I am not sure why it is? I have attached a screen-shot to this comment. 

I have seen there are three groups (root, admin, user) in SYSTEM/USER in the webUI. I have changed the read permission of admin and user to allow. But it does not help.

I would be appreciated for your further comments and help.

Kind regards

Z WH

by anonymous
Hello,

I'm sorry if I'm getting this wrong, but I can't see very well your photo. /tmp is a Linux registry, the router uses an OS based on Linux so the file system works in the same way as any Linux file system and are the same commands to move into folders and different directions. So to enter a directory you have to use the command "cd /tmp" and you should be able to go to that directory.

About your other question, using the Modbus Serial Master the information that the router is getting from a slave device is being stored on that directory, "/tmp/modbus_db" . And about the registries to get certain information inside the Modbus service, they deppend on the slave device.
by anonymous

Hello,

Thank you very much on your comments.

I have opened the /tmp directory, but I did not find the file "modbus_db" file within this folder. I have attached a screenshot to this comment (Hope it is clear enough). I would like to ask: 

1. Is this file generated during the manufacture process, or it generated after the user setup?

2. I have found another file " mdcollectd.db". Should be this file? I have found two rows of data with ID number "28" and "29". Should these be the corresponding register number for storing slave RS-485 data?

3. By the registries inside the Modbus service, why would they depend on the slave device? Since the structure of my RS-485 slave is: (external AD -> MCU -> UART to RS485 chip -> TRB 245). There is no specific registries on UART to RS485 chip. I can measure the output signal from UART to RS485 chip.

I would be appreciated for your further comments and help.

Kind regards

Z WH

by anonymous

Hello, 

Let me answer your questions. 

About number one, the file should be created after the setup of the service.

And about numbers two and three, the file that you can find in this registry "/tmp/modbus_db" is a hidden file. If you want to see the file I would recommend using an SSH terminal and entering the complete command so you can see that file.  If you want to transfer that file from the router to your computer you can use an SSH file transfer software, I recommend WinSCP it is easy to use, but it is important that you write the complete address or command so you can find the file.