05.10.2022, 09:55
Hello Admin,
We soon will be working on a project where we have to read out multiple energy meters over modbus rtu and visualize some values in the LM. This is about multiple sites.
The installer was proposed to use some rtu to tcp converters and then to use one LM to get all data.
Now we want to propose the use of multiple LMs to directly poll the data from the modbus rtu bus. Therefore I have some questions before we proceed with the solutuion.
- Can both RS485 ports be enabled and used at the same time? (normally yes but wanted to verify)
- Can we connect up to 32 devices on one RTU bus line?
- What is the maximum allowed length of one bus line so that there are no failures in reading. The installer is using CAT6a UTP with shield for exterior use.
We know in some cases (in this project) the lenght is around 200m.
- Is there CPU limitation in getting the data if lets say we have the maximum allowed amount of devices on each bus line.
The polling will not be very fast or what would be best to set for energy values (15min) and real time values like U,I,Cosφ...
Thank you in advnace for your reply.
We soon will be working on a project where we have to read out multiple energy meters over modbus rtu and visualize some values in the LM. This is about multiple sites.
The installer was proposed to use some rtu to tcp converters and then to use one LM to get all data.
Now we want to propose the use of multiple LMs to directly poll the data from the modbus rtu bus. Therefore I have some questions before we proceed with the solutuion.
- Can both RS485 ports be enabled and used at the same time? (normally yes but wanted to verify)
- Can we connect up to 32 devices on one RTU bus line?
- What is the maximum allowed length of one bus line so that there are no failures in reading. The installer is using CAT6a UTP with shield for exterior use.
We know in some cases (in this project) the lenght is around 200m.
- Is there CPU limitation in getting the data if lets say we have the maximum allowed amount of devices on each bus line.
The polling will not be very fast or what would be best to set for energy values (15min) and real time values like U,I,Cosφ...
Thank you in advnace for your reply.