GE Industrial Solutions WattStation Pedestal EVSE Charger MODBUS Register Mapping Guide - Manual (Page 10)

WattStation TM EV Charger MODBUS Register Guide
10 GE Energy ©2012 GE Company All Rights Reserved
• M MO OD DBBU USS FFC C 33 RReeqquueesstt
Field Length (bytes) Value (hex)
Function Code 1 0x03
Starting Address 2 0x0000 to 0xFFFF
Number of Registers 2 0x1 to 0x7D (1 to 125)
Table – 3.2
The register data in the response message are packed as two bytes per register, with the binary
contents right justified within each byte.
For each register, the first byte contains the high order bits and the second contains
the low order bits.
• MODBUS FC 3 Response
Field Length (bytes) Value (hex)
Function Code 1 0x03
Byte Count 1 2 × N
Register Value 2 × N
Table – 3.3
Note: N is the number of registers specified in the request.
3.3.2
Function Code 4 (0x04): Read Input registers (multiple)
Function code 4 is used to read the contents of a contiguous block of input registers (read only) in
EVSE. The MODBUS Function code 4 Request PDU specifies the starting register address and the
number of registers to be read. In the PDU Registers are addressed starting at zero. Therefore
registers numbered 1-16 are addressed as 0-15.
• MODBUS FC 4 Request
Field Length (bytes) Value (hex)
Function Code 1 0x04
Starting Address 2 0x0000 to 0xFFFF
Number of Registers 2 0x1 to 0x7D (1 to 125)
Table – 3.4
The register data in the response message are packed as two bytes per register, with the binary
contents right justified within each byte. For each register, the first byte contains the high order bits
and the second contains the low order bits.