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You will need at least one modbus RTU/TCP gateway depending on the RTU slaves the gateway can handle. Google for suppliers of Modbus RTU/TCP gateways. I have never seen gateways with more than 2 ethernet ports (This doesn't mean they don't exist) so you probably also need an ethernet switch.

You calculate the CRC using the bytes starting from the address byte up to the last data byte. So in your case you use 01 03 10 00 00 01 or 07 02 10 01 00 01. The procedure for calculating the CRC is: 1. Load a 16-bit register with FFFF hex (all 1's). Call this the CRC register. 2...

If a modbus slave can not answer your message, it will respond with the original command (03) and set the highest bit in that command (83). The following number (09) is the exception code. Exception code 09 is not a valid modbus exception, maybe you can ask the supplier of the slave if they are...

This command will give a valid response. The first 2 bytes will contain the UINT16 value. The next 4 bytes represent the IEEE value of the floating point, and the last 2 bytes contain the last UINT16 value. Possibly you have to do some byte or word swapping. Address 01 and 02 contains the...

If you do not receive a response from the slave at all you should focus on the RS485 connection and/or communication settings. Verify baud rate, data bits, stop bits,... are correct. Is the Modbus address in the VFD configured correctly? Try switching that A and B wires. If the slave is...

Hi, I don't know how other companies are doing this but I know there are a lot of different interpretations. But on the other hand I don't see a problem with your customers request. By padding the unused data with zero's he can get a range of coils/registers in one telegram what will...

Hi, There are some problems with the telegrams you are sending to the Daikin AC. -First of all you use address \xA4\x11 (42001), this should be \x07\xD0 (2000). Registers 4xxxx are holding registers and you do not have to use this with modbus commands. Same for input registers do not use...

Hi, Since you want a low cost solution i think you will have to do some programming in p.e. .NET. Modbus is an open protocol with plenty of information available so it shouldn't be a problem to write an application to retrieve data from the PLC. To store data you could use an SQL database...

Hi, You do not need to connect VCC. In theory you only need to connect the A and B lines since RS485 is a differential bus but it is always preferred to also connect GND.

Routing is automatic. All H8830 devices create one RS485 network so all devices on the RS485 network needs a unique modbus address. Also every H8830 needs a unique modbus address since they also can be used as modbus slaves. I don't think Schneider has WIFI bridges but you can find industrial...

One H8830 can handle 32 modbus slaves. If you want to connect 82 modbus slaves you will need at least 3 devices depending on the location of the slaves. See http://www.veris.com/docs/Datasheets/H8830_d01141.pdf for more application examples. Instead of using the H8830 also consider...

Hi, This is often done. Most of the masters have some scaling functionality so they should be able to convert this value. Only disadvantage is the accuracy because you have consider the 16 bit data format but in most cases this is not a big issue.

I assume you use the ROC809 as a slave. You have to configure registers in the ROC. In the Roclink software go to 'Configure', 'Modbus'. Go to the Registers TAB. For digital values use table 1 and/or 2, for analog table 3, 4, 16. These tables are the modbus commands you are using. Fill in the...