WAGO 750-8207 Manual page 288

288 MODBUS – CODESYS 2
10.4.4.3 MODBUS Mapping for Read Register Services FC3, FC4, FC23
The table below outlines the mapping for the MODBUS-reading, register-oriented
services:
• FC3 – Read Holding Registers,
• FC4 – Read Input Registers,
• FC23 – Read/Write Multiple Registers
Table 208: MODBUS Mapping for Read Register Services FC3, FC4, FC23
MODBUS Address
(hexadecimal values
in parentheses)
0 ... 999
(0x0000 ... 0x03E7)
1000 ... 1999
(0x03E8 ... 0x07CF)
2000 ... 4095
(0x07D0 ... 0x0FFF)
4096 ... 12287
(0x1000 ... 0x2FFF)
Manual
Draft version 1.2.1 from 2017-09-13, valid from FW Version 02.06.20(09)
IEC 61131 Description
Address
%IW1000 ... MODBUS Output:
%IW1999 1000 PFC input registers/words in the
2 kB MODBUS output process image in
the PII.
Note: In this area, the read register
services return the content from the PII.
%QW1000 ... MODBUS Input:
%QW1999 1000 PFC output registers/words in the
2 kB MODBUS input process image in
the PIO.
Note on FC23:
Only the Read portion of this service can
be executed.
Inhibited to MODBUS-only area for
register-oriented read access. Register-
based read services for this area are
acknowledged by the MODBUS slave
with the MODBUS exception code
"ILLEGAL DATA ADDRESS" (0x02).
No IEC 61131 Information and configuration registers:
address Not all MODBUS addresses in this range
are valid.
Valid MODBUS addresses are described
in the Section "WAGO MODBUS
Registers".
Access to invalid addresses are
acknowledged by the MODBUS slave
with the MODBUS exception code
"ILLEGAL DATA ADDRESS" (0x02).
Note on FC23:
The Write portion of this service can only
be executed for registers that data can
be written to.
WAGO-I/O-SYSTEM 750
750-8207 PFC200 CS 2ETH RS 3G