Diagnostic Functions; Cable Types; Installation Guidelines; Checking The Profibus Cabling - turck IO-LINK MASTER User Manual

System overview

Cable types

The bus cable of the PROFIBUS-DP network is a special shielded twisted data cable
according to RS485 standards. The data transmission rate is 12 Mbps max.

Installation guidelines

When mounting the modules and routing the cables please observe the technical guidelines
of the PROFIBUS user organization concerning PROFIBUS-DP/FMS (see
www.profibus.com).

Checking the PROFIBUS cabling

A PROFIBUS cable (or the cable segment if repeaters are used) can be tested with a few resis-
tance measurements. For this the cable should be disconnected from all stations:
Resistance between "A" and "B" at the beginning of the cable: approx. 110 Ω
Resistance between "A" and "B" at the end of the cable: approx. 110 Ω
Resistance between "A" at the beginning and "A" at the end of the cable: approx. 0 Ω
Resistance between "B" at the beginning and "B" at the end of the cable: approx. 0 Ω
Resistance between shield at the beginning and shield at the end of the cable: approx. 0 Ω
If these measurements are successful, then the cable can be used according to standards.
However, if there are further disturbances on the bus, electromagnetic interference should be
considered as cause. Please also observe the installation guidelines of the PROFIBUS user
organization (www.profibus.com)

Diagnostic functions

The comprehensive diagnostic functions of PROFIBUS-DP allow fast error localization.
The PROFIBUS-DP diagnosis is divided into three levels:
Table 3: Type of diagnosis
PROFIBUS-DP
station-related diagnostics Messages concerning the general operational readiness of a
diagnosis
Module-related
diagnostics
Channel-related diagnos-
tics
The PROFIBUS slaves of the BL20 series support the diagnostic functions of PROFIBUS-DP.
D301171 - IO-Link master 1108
Note
Premoulded PROFIBUS-DP cables simplify network installation, shorten set-up
times and reduce wiring errors. TURCK offers an extensive and varied product
spectrum for this purpose.
The ordering information on the available cable types can be taken from the respec-
tive product catalogue.
Description
bus node.
These messages indicate that there is a diagnostic message
within the a certain I/O area (e.g. 8 bit output module) of a bus
node.
Here the error cause of a single input/output bit, i.e. relating to
a single channel, is indicated.
Example: "Short-circuit at output 2"
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