Modbus Register Addressing; Modbus Function Codes; Data Formats - Eaton Power Xpert Gateway Series 1000 Card User Manual

MODBUS REGISTERS

Modbus Register Addressing

This section describes Modbus function codes, data formats, and data
addressing.

Modbus Function Codes

The PDU/RPP registers are read using Modbus Function Codes (FC). For
most PDU/RPP registers, FC 04 is used. The PDU/RPP supports the
following hex function codes:
Table 1. Function Codes

Data Formats

Modbus programs usually provide an option for viewing various data
types. Refer to your Modbus program documentation for detailed
information on viewing data options.
A register is 16 bits (two bytes). The PDU/RPP supports the following
data types:
S
S
S
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EATON Power Xpert
FC Hex Description
01 0x01 Read Coil Status
02 0x02 Read Discrete Inputs
03 0x03 Read Holding Registers
04 0x04 Read Input Registers
05 0x05 Write Single Coil
06 0x06 Write Single Register
0F 0x0F Write Multiple Coils
10 0x10 Write Multiple Registers
STRING – A string of ASCII characters (two per register). Consult the
Size parameter to find the string's length for a given entry (it is a
multiple of two so that entries are register-aligned).
FLOAT – A 32-bit IEEE754 floating point number. FLOATs are always
two registers.
UINT – An unsigned integer. Consult the Size parameter to find the
integer's size for a given entry (it is a multiple of two so that entries
are register-aligned).
® Gateway Series 1000 Card User's Guide
Use
Supported for compatibility purposes
Single input data, such as alarms and
discrete contacts
Supported for compatibility purposes
Analog data (most string and numeric
data types), such as voltage
For future use
For future use
For future use
For future use
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