Which data types are supported in Modbus RTU for reading and writing values?

Which data types are supported in Modbus RTU for reading and writing values?

• A. Input Registers and Holding Registers
• B. Coils, Discrete Inputs, Input Registers, and Holding Registers
• C. Coils (bits) and Discrete Inputs
• D. Coils (bits) only

Answer: (B)

Modbus RTU defines four data types for exchanging values: coils (single-bit status that can be read and written), discrete inputs (single-bit status that is read-only), input registers (16-bit data that is read-only), and holding registers (16-bit data that can be read and written). The option that lists all four data types is best because it accurately reflects every data space Modbus RTU exposes. Writing is possible on coils and holding registers, while reading can be done from all four types, but the complete data model includes all four categories. Choices that omit one or more data types wouldn’t capture the full Modbus RTU data model.

Modbus RTU defines four data types for exchanging values: coils (single-bit status that can be read and written), discrete inputs (single-bit status that is read-only), input registers (16-bit data that is read-only), and holding registers (16-bit data that can be read and written). The option that lists all four data types is best because it accurately reflects every data space Modbus RTU exposes. Writing is possible on coils and holding registers, while reading can be done from all four types, but the complete data model includes all four categories. Choices that omit one or more data types wouldn’t capture the full Modbus RTU data model.