WAGO 750-880, Manual

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WAGO-I/O-SYSTEM 750 Fieldbus Communication 243
750-880, 750-880/025-000 ETHERNET Programmable Fieldbus Controller
Manual
Version 1.0.1
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12.2.5.1 Accessing Register Values
You can use any MODBUS application to access (read from or write to) register
values. Both commercial (e.g., "Modscan") and free programs (from
) are available.
The following sections describe how to access both the registers and their values.
12.2.5.2 Watchdog Registers
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 used to setup the watchdog by the master
(Register addresses 0x1000 to 0x1008).
By default, the watchdog is not enabled when you turn the controller on. To
activate it, the first step is to set/verify the desired time-out value of the Watchdog
Time register (0x1000). Second, the function code mask must be specified in the
mask register (0x1001), which defines the function code(s) that will reset the
timer. Finally, the Watchdog-Trigger register (0x1003) must be changed to a non-
zero value to start the timer.
Table 131: MODBUS registers (Continuation)
Register
address Access Length
(Word)
Description
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 I/O modules (module 0…64)
0x2031 R 64 Description of the connected I/O modules (module 65…128)
0x2032 R 64 Description of the connected I/O modules (module 129…192)
0x2033 R 63 Description of the connected I/O modules (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