Profibus system engineering and monitoring - Andy Verwer and Peter Thomas
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Transcript of Profibus system engineering and monitoring - Andy Verwer and Peter Thomas
System
Engineering &
Network
Monitoring
Andy Verwer,
Verwer Training
& Consultancy,
Peter Thomas,
Control
Specialists Ltd
United Kingdom
Practical Aspects
of PROFIBUS,
PROFINET and
IO-Link,
Manchester,
29th March 2017
System Engineering & Network Monitoring, Andy Verwer, page 2Practical Aspects of PROFIBUS/NET, March 2017
Overview
This presentation will look at PROFIBUS and PROFINET systems
and examine the types of problems and failures that are
experienced.
We will examine how available devices can provide:
Network health monitoring, performance and diagnostics.
Engineering Access for device replacement, set-up, calibration
and diagnostics.
We will then demonstrate a couple of solutions that are
available for PROFIBUS and PROFINET monitoring.
System Engineering & Network Monitoring, Andy Verwer, page 3Practical Aspects of PROFIBUS/NET, March 2017
PROFIBUS and PROFINET are very reliable and cost effective
technologies.
It is common to find extensive installations comprising
thousands of PROFIBUS devices operating on complex
networks.
The reliable operation of these networks is essential to
maintaining plant availability and productivity.
So, what can go wrong?
PROFIBUS and PROFINET
System Engineering & Network Monitoring, Andy Verwer, page 4Practical Aspects of PROFIBUS/NET, March 2017
What can go wrong?
In our experience about 80% of problems are caused by
physical layer, cabling and connector problems:
Shorts and open-circuits;
Water and chemical ingress;
Termination problems (mainly PROFIBUS);
Poor network layout;
Etc.
The remaining 20% of problems are due to:
Interference pickup (EMC);
Power supply failure or overloading;
Software compatibility and security (mainly PROFINET);
Device failure (quite rare).
System Engineering & Network Monitoring, Andy Verwer, page 5Practical Aspects of PROFIBUS/NET, March 2017
Quite often users are unaware that their system has errors
because the robustness of PROFIBUS and PROFINET can hide
developing faults.
Green light –
all must be ok!
But by then it is too late!
Communication faults
Only when the rate of data corruption reaches a critical
threshold will the fault become visible.
System Engineering & Network Monitoring, Andy Verwer, page 6Practical Aspects of PROFIBUS/NET, March 2017
Permanent faults are relatively easy to fix.
Because the fault disappears when we've fixed it!
Intermittent faults can be a nightmare!
Because we cannot be sure that we have fixed it.
We may seem to have cured the problem, but then it comes
back again later!
Intermittent faults require long-term monitoring to check that
the fault is cured.
Statistical reporting over an extended period can be useful.
Intermittent Faults
System Engineering & Network Monitoring, Andy Verwer, page 7Practical Aspects of PROFIBUS/NET, March 2017
Fault finding & health checking tools
A range of tools are available for PROFIBUS and PROFINET
system health checking and troubleshooting.
Analysers are useful for indicating protocol errors such as
repeated, missed or corrupted messages.
Waveform visualisation can help to diagnose physical layer
problems.
Advanced diagnostic tools can help to diagnose performance
degradation and network loading problems.
Unfortunately such tools are only of use when plugged in to
the network and operated by a competent engineer!
System Engineering & Network Monitoring, Andy Verwer, page 8Practical Aspects of PROFIBUS/NET, March 2017
Health checking is an important part of the commissioning and
maintenance strategy for your plant.
The health check will help to find non-critical and intermittent
faults that are not obvious.
A health check should be carried out immediately after
commissioning. We also strongly recommend repeating the
health check at intervals.
How much better to integrate the health checking tools into the
network?
To give permanent monitoring of system health.
Automatically report failures.
Give pre-warning of impending failures and performance
degradation.
System Health Checking
System Engineering & Network Monitoring, Andy Verwer, page 9Practical Aspects of PROFIBUS/NET, March 2017
Permanent monitoring tools
A number of tools have appeared on the market which are
designed to be permanently connected to the network to
provide 24/7 network monitoring.
For PROFIBUS systems:
PROCENTEC COMbricks
network monitor
(up to four networks,
20 DP or PA segments)
Indu-Sol’s PROFIBUS
INspektor
(one DP segment)
PROCENTEC
diagnostic hubs
(up to five DP
segments)
Siemens’ diagnostic
repeater
(two DP segments)
Softing’s TH LINK
PROFIBUS
(one DP segment)
System Engineering & Network Monitoring, Andy Verwer, page 10Practical Aspects of PROFIBUS/NET, March 2017
Permanent monitoring tools
For PROFINET systems:
Indu-Sol’s
PROFINET
INspektorSofting’s
TH LINK
PROFINET
PROCENTEC’s
PROFINET monitor,
(to be announced at
the Hannover Fair,
next month)
Softing’s
PROFINET
monitor
System Engineering & Network Monitoring, Andy Verwer, page 11Practical Aspects of PROFIBUS/NET, March 2017
Head Station
with ProfiTrace
built in
Repeater
modules with
optional
‘scope and
redundancy
PROFIBUS
DP slave
modules
IO modules
digital, relay,
analogue etc.
PROFINET IO
device
modules
Optical link
modules
(1 or 2
channel)
mix and match to produce the required functionality
PA module
Coupler
and/or MBP
monitor with
‘scope
COMbricks
COMbricks is a modular repeater and gateway system from
PROCENTEC with built-in PROFIBUS monitor and analyser
functionality accessible over Ethernet.
The modules available include:
System Engineering & Network Monitoring, Andy Verwer, page 12Practical Aspects of PROFIBUS/NET, March 2017
Head
Station
Ethernet
Each of the four segments
can have up to 31 devices
connected.
But each channel can be
connected to a separate
network if desired, allowing
up to 4 separate networks to
be monitored
simultaneously.
2 channel
repeater
2 channel
repeater
E.g. 1 – DP Hub/Monitor
ProfiTrace - built into the
head station. Can monitor
all 4 segments
simultaneously. Accessible
remotely over Ethernet.
System Engineering & Network Monitoring, Andy Verwer, page 13Practical Aspects of PROFIBUS/NET, March 2017
E.g. 2 – DP/PA coupler/monitor
1 channel
‘scope
repeater
Head
Station
PA coupler
moduleThis unit can be used as a
stand-alone DP/PA coupler
with both DP and PA
segments monitored by
the head station.
The unit acts like a
transparent link allowing
high-speed DP operation
(up to 1.5Mbit/s)
Ethernet
DP
(RS485)
PA
(MBP)
The same unit can also
simply be configured to
just monitor the signals on
an existing coupler or link.
These modules incorporate
an oscilloscope function
allowing waveform
visualisation and bar chart.
System Engineering & Network Monitoring, Andy Verwer, page 14Practical Aspects of PROFIBUS/NET, March 2017
Simple web browser
27 March 2017
ProfiTrace streaming
FDT/DTM Tools
OPC / SCADA Alarm handling
All provided as standard
within the head station.
Remote monitoring via Ethernet
System Engineering & Network Monitoring, Andy Verwer, page 15Practical Aspects of PROFIBUS/NET, March 2017
Demonstration
System Engineering & Network Monitoring, Peter Thomas, page 16Practical Aspects of PROFIBUS/NET, March 2017
PROFINET Diagnostics
The switched-based architecture of
a PROFINET network means that it is
very important to consider how
diagnostic tools will connect to the
network.
This is because switches learn the
MAC addresses of the devices to
ensure that traffic is only
transmitted to the relevant port on
the switch.
By default, an unused port will only
ever see broadcast traffic and will
therefore be useless for monitoring
purposes.
To PROFINET
IO Devices
Switch
IO Controller
Spare Port –
Sees broadcast
Traffic Only !
System Engineering & Network Monitoring, Peter Thomas, page 17Practical Aspects of PROFIBUS/NET, March 2017
PROFINET Diagnostics
When using a Conformance Class B
PROFINET switch, one option is to
assign an unused port as a mirror
port.
This will “copy” all traffic from a
given port to the mirror port and
thereby allow diagnostic tools to
monitor the traffic in/out of the
monitored port.
Note that under periods of high
demand the transfer of traffic to the
mirrored port cannot be guaranteed.
To PROFINET
IO Devices
Switch
IO Controller
Set to “Mirror” Port,
connect diagnostic
tools here
System Engineering & Network Monitoring, Peter Thomas, page 18Practical Aspects of PROFIBUS/NET, March 2017
PROFINET Diagnostics
A better solution is to include a
hardwired monitor and access
point.
This is completely transparent to
the PLC but allows permanent or
temporary tools to be connected
to the network without
disruption.
The monitoring function
operates even when tools are
disconnected.
It also has the advantage of
leaving unused switch ports
available for future use.
IO Controller
To PROFINET
IO Devices
Switch
Monitor
Monitoring and
diagnostic tools
connected here
Spare Port
System Engineering & Network Monitoring, Peter Thomas, page 19Practical Aspects of PROFIBUS/NET, March 2017
Demo - PROFINET INspektor
24vPSU
IO Controller
PROFINETINSPEKTOR
PROFINETSWITCH
TOTRAININGRACKS VIA EXTERNALSWITCHES
PROFINETACCESS POINT
ETHERNET WIRELESS ROUTER
System Engineering & Network Monitoring, Peter Thomas, page 20Practical Aspects of PROFIBUS/NET, March 2017
PROFINET – Quality Criteria
System Engineering & Network Monitoring, Peter Thomas, page 21Practical Aspects of PROFIBUS/NET, March 2017
Demonstration