Diagnostics; Diagnostics For The Modbus Master; Diagnostics For The Runtime System; Diagnostics For The Error Server - WAGO I/O SYSTEM 750 Manual

288 MODBUS – CODESYS 2
9.6

Diagnostics

9.6.1

Diagnostics for the MODBUS Master

The status of the PLC, or of the control system, can be queried by the MODBUS
master by reading the WAGO-specific register 0x1040 – "PLC Status" using
MODBUS services FC3 (Read Holding Registers) or FC4 (Read Input Registers).
The WAGO-specific register 0x1040 – "PLC Status" is explained in the Section
"PLC Status Registers".
The status of the MODBUS Watchdog can be requested using a register service
(FC3 or FC4) with a query to the WAGO-specific register 0x1101 – "Watchdog
Status Register". Information about this is given in the Section "MODBUS
Watchdog".
The MODBUS service "Get Communication Event Counter" (FC11) is not
supported in the current MODBUS slave Version V1.0.
9.6.2

Diagnostics for the Runtime System

Diagnostics for the MODBUS slaves can be executed by integrating the
CODESYS library "BusDiag.lib" via the runtime system. The required function
block, "DiagGetBusState() indicates the status of the fieldbus (here MODBUS)
and is located in this library. Details about this function block are provided both in
this document and in the online Help function for CODESYS.
9.6.3

Diagnostics for the Error Server

The MODBUS slave also supports the error service implemented in the PFC and
generates diagnostic messages, which are stored permanently (in a file), or
temporarily (in the RAM) and can be displayed directly via the WBM client. The
following diagnoses are generated by the MODBUS slave:

Table 206: Diagnostics for the Error Server

Diagnostics
ID
0x00090000
0x00090001
0x00090002
0x00090003
0x00090004
0x00090005
Diagnostic text
Modbus Slave
library loaded
Modbus Slave
library closed
Modbus Slave
TCP started
Modbus Slave
TCP start failed
Modbus Slave
TCP terminated
Modbus Slave
UDP started
Version 1.1.0, valid from FW Version 02.06.20(09)
750-8208 PFC200 CS 2ETH RS CAN DPM
Method of Explanation
saving
Temporary MODBUS slave library has
been successfully loaded.
Temporary MODBUS slave library has
been successfully unloaded.
Temporary MODBUS slave successfully
started in TCP mode.
Permanent Starting the MODBUS slave in
the TCP mode failed.
Temporary MODBUS slave TCP mode
successfully terminated.
Temporary MODBUS slave successfully
started in UDP mode.
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