MODBUS Protocol Quiz :Test Your Knowledge

A MODBUS gateway converts MODBUS messages to other communication protocols (e.g., from MODBUS RTU to MODBUS TCP/IP).

MODBUS over TCP/IP can cover greater distances using the existing network infrastructure.

Floating-point data is typically represented using two consecutive 16-bit registers in MODBUS.

MODBUS Exception Codes indicate errors in communication or request processing.

Controllers, such as PLCs or SCADA systems, can act as MODBUS masters.

In MODBUS TCP/IP, data is transmitted in IP packets.

After the function code, the data field follows in a MODBUS message.

Function code 03 is used to read holding registers.

PDU stands for Protocol Data Unit, which contains the function code and data in a MODBUS message.

Function code 16 is used to write multiple registers.

MODBUS RTU uses binary encoding, whereas MODBUS ASCII uses ASCII characters for data encoding.

MODBUS over serial communication operates in a master-slave configuration.

In MODBUS, a coil refers to a single bit output.

Function code 11 is not a valid MODBUS function code.

A MODBUS RTU byte consists of 8 bits.

The maximum number of coils that can be read in a single MODBUS request is 2000.

Function code 04 is used to read input registers.

The Unit Identifier is used to identify the slave device in a MODBUS TCP/IP network, especially when a MODBUS gateway is used.

A colon (:) character indicates the start of a frame in MODBUS ASCII mode.

Function code 05 is used to write to a single coil.

MODBUS RTU uses a 16-bit Cyclic Redundancy Check for error checking.

Function code 02 is used to read the status of discrete inputs.

A silent interval of at least 3.5 character times marks the end of a message in MODBUS RTU.

MODBUS TCP/IP uses port 502 for communication.

MODBUS is an application layer protocol, providing the rules for organizing and interpreting the data that applications exchange.