GE Industrial Solutions WattStation Pedestal EVSE Charger MODBUS Register Mapping Guide - Manual (Page 13)

WattStation TM EV Charger MODBUS Register Guide
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The Normal MODBUS function code 23 Response PDU contains the data from the group of registers
that were read. The byte count field specifies the quantity of bytes to follow in the read data field.
• MODBUS FC 23 Response (N = Quantity of registers to Read)
Field Length (bytes) Value (hex)
Function Code 1 0x17
Read Byte Count 1 2 × N
Read Registers Value N × 2 Value
Table – 3.11
3.4 MODBUS Exception Codes Supported
In this version architecture design, the MODBUS in EVSE supports the following Exception Codes as
shown in following table.
Exception Code Exception Code Name Description
1 Illegal Function Code The function code received in the MODBUS
request is not an allowable action in EVSE.
2 Illegal Data Address The data address received in the MODBUS
request is not an allowable address in EVSE.
3 Illegal Data Value The data address received in the MODBUS
Write request is not an allowable value for
EVSE.
4 Slave Device Failure An unrecoverable error occurred when the
server (or the slave) was attempting to perform
the requested action.
Table – 3.12
• M
MO OD DBBU USS EExxcceeppttiioonn RReessppoonnssee
Field Length (bytes) Value (hex)
Function Code 1 0x80 | Function Code
(or pure addition operation)
Exception Code 2 1-6
Table – 3.13