Enumeration MetadataMODBUSEntity

Enumeration Members

Coil: "Coil"

Coil (0xxxx)

Data Type: Single bit
Address Range: 00001–09999
Access: Read/Write
Typical Use: Digital outputs (on/off), relay states, discrete control values.
Related FCs: FC1 (Read Coils), FC5 (Write Single Coil), FC15 (Write Multiple Coils).

Device: "Device"

Device (Identification via FC43/14)

Data Type: Structured identification objects
Address Range: Not bound to coil/register ranges
Access: Read-Only
Typical Use: Provides information about the Modbus device itself (e.g., Vendor Name, Product Code, Revision, Serial Number).
Related FCs: FC43/14 (Read Device Identification).

Unlike coils or registers, the Device entity is not tied to a memory address range but represents metadata about the device.

DiscreteInput: "DiscreteInput"

Discrete Input (1xxxx)

Data Type: Single bit
Address Range: 10001–19999
Access: Read-Only
Typical Use: Digital inputs such as sensor contacts, push buttons, limit switches.
Related FCs: FC2 (Read Discrete Inputs).

HoldingRegister: "HoldingRegister"

Holding Register (4xxxx)

Data Type: 16-bit word
Address Range: 40001–49999
Access: Read/Write
Typical Use: Analog outputs, configuration parameters, counters.
Related FCs: FC3 (Read Holding Registers), FC6 (Write Single Register), FC16 (Write Multiple Registers), FC22 (Mask Write Register).

InputRegister: "InputRegister"

Input Register (3xxxx)

Data Type: 16-bit word
Address Range: 30001–39999
Access: Read-Only
Typical Use: Analog input values such as temperature, pressure, or flow sensors.
Related FCs: FC4 (Read Input Registers).