Modbus Protocol -Matrikon OPC

Dear Team,

We have 400 Energy meter support Mobdus RTU RS-485 .
One Matrikon OPC server support 400 Energy Meter?
What is the Data update rate.

please provide techincal informartion for How many devices coonected to one OPC server or any limitation .

Read/Write register .

I can't comment specifically on the Matrikon OPC server, but there are a couple other limitations based on the protocols being used (RS-485 and Modbus RTU).

Electrically, RS-485 allows up to 32 Unit Loads to be connected to a single bus. While historically, each device would be 1 Unit Load, today, many RS-485 devices are only a fraction of a unit load, such as 1/2, 1/4, 1/8, or 1/10. For example, if each device is 1/4 Unit Load, you could have up to 128 devices on the bus. Of course, this limitation can be overcome by the use of RS-485 repeaters, which split the network into 2 or more buses, each with a 32 Unit Load limit.

Logically, the Modbus RTU protocol supports slave addresses from 1 - 247. Therefore, from the perspective of the Modbus protocol, you can have at most 247 slaves connected to a single Modbus network.

Regarding data update rate, the greatest contributors to this are typically the slave response time and the master's inter-poll delay and processing times. For devices, such as gateways, that constantly make requests to synchronize all mapped data from the Modbus devices, the update rate heavily depends on the number of registers (data) mapped. Now, this may not apply to the Matrikon OPC server, because it may make Modbus requests on-demand based on the OPC requests it receives (it may behave more like a router than a gateway).