166
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MODBUS Functions
Internal
Variables
WAGO-I/O-SYSTEM
750
ETHERNET TCP/IP
0x2000 R
1
Constant
0x0000
0x2001 R
1
Constant
0xFFFF
0x2002 R
1
Constant
0x1234
0x2003 R
1
Constant
0xAAAA
0x2004 R
1
Constant
0x5555
0x2005 R
1
Constant
0x7FFF
0x2006 R
1
Constant
0x8000
0x2007 R
1
Constant
0x3FFF
0x2008 R
1
Constant
0x4000
0x2010 R
1
Firmware
version
0x2011 R
1
Series
code
0x2012 R
1
Controller
code
0x2013
R
1
Firmware versions major revision
0x2014
R
1
Firmware versions minor revision
0x2020
R
16
Short description controller
0x2021
R
8
Compile time of the firmware
0x2022
R
8
Compile date of the firmware
0x2023
R
32
Indication of the firmware loader
0x2030
R
65
Description of the connected busmodules (module 0–64)
0x2031
R
64
Description of the connected busmodules (module 65-128)
0x2032
R
64
Description of the connected busmodules (module 129-192)
0x2033
R
63
Description of the connected busmodules (module 193-255)
0x2040
W
1
Software reset (Write sequence 0x55AA or 0xAA55)
0x2041 W
1
Format
Flash-Disk
0x2042
W
1
Extract HTML sides from the firmware
0x2043 W
1
Factory
Settings
4.2.5.1 Description of the internal variables
4.2.5.1.1 Watchdog (Fieldbus failure)
The watchdog monitors the data transfer between the fieldbus master and the
controller. Every time the controller receives a specific request (as define in
the watchdog setup registers) from the master, the watchdog timer in the
controller resets.
In the case of fault free communication, the watchdog timer does not reach its
end value. After each successful data transfer, the timer is reset.
If the watchdog times out, a fieldbus failure has occurred. In this case, the
fieldbus controller answers all following MODBUS TCP/IP requests with the
exception code 0x0004 (Slave Device Failure).
In the controller special registers are use to setup the watchdog by the master
(Register addresses 0x1000 to 0x1008).