cpp – Process technology for the chemical industry 02.2020

The analogue input module Pnoz m EF 4AI from the product range of
configurable safe small controllers Pnozmulti 2 offers faster processing
and optimised diagnostics
Despite the expanding machine size and the increasing level of automation,
user programs can still be manageable with the help of the
Pnozmulti Configurator and by simulating the application
for connecting transducers or encoders with
standardised current signals. Arithmetic
functions such as averaging and calculating
differential pressure make application easier
and enable faster, more precise diagnostics.
Up to six analogue values per module can
be transferred to a fieldbus, so it is possible
to intervene in the process more quickly, if
necessary.
Analogue values can also be displayed and
evaluated in combination with the visualisation
software Pasvisu, also from Pilz.
Fewer downtimes are the result, along with
faster configuration and commissioning.
Automation projects can be configured and
visualised with Pnozmulti 2 in conjunction
with the web-based visualisation software;
the full function range can be used. Operators
and service personnel obtain a comprehensive
overview of the entire plant, including
numerous diagnostic options, both
locally and via remote access. As a result,
faults or malfunctions can be detected and
rectified quickly, plus downtimes are reduced.
Potential savings during configuration
In addition to the analogue modules, the
software tool Pnozmulti Configurator also
supports process industry users during configuration,
documentation and commissioning.
You simply need to select the necessary
function blocks in order to establish the desired
connections via drag & drop. The program
then checks each action independ -
ently for plausibility. It also helps with the
early detection of errors within projects:
from Version 10.9, an offline simulation
program in the Pnozmulti Configurator
checks the completed project on the computer,
before the newly created program is
required to prove its functionality on the
machine. The simulation program detects
logic errors prior to commissioning. The actual
procedure on the machine as it is running
is effectively simulated – offline and
without hardware, in the office so to speak.
Simple simulation
The logic connections are simulated and
tested to avoid drop out and downtimes and
to save time when the system is first deployed
on the plant. The connection line between
two function blocks may be forgotten
in one section of the program. Practical
example: an emergency stop pushbutton as
an input controls an output in the configuration.
Other functions, and therefore other
lines, are planned in between them. If one
line is forgotten, nothing happens later
when the emergency stop is operated. So
the simulation comes into play even during
development. The opportunity for simulation
means that users can guarantee that
the configuration of the safety controller is
“fault-free” and that the correct functioning
of the program logic is verified before it is
used live. Simulation helps users to maintain
an overview of whether the configuration is
correct, particularly when there are more
than two or three safety functions on the
machine.
Simple logic elements, counters and operating
modes such as continuous cycle are calculated
automatically as a first step. What’s
more it’s even possible to simulate the entire
application if elements that cannot be
simulated are brought to the required state
by forcing the outputs (fixed signal state is
specified). Not every input needs to be defined.
One special feature: in the Pilz simulation
it is possible to specify a machine’s
cycle time; there is an integrated time controller.
Time sequences can be simulated:
the seconds that an axis needs to move into
position, for example.
Whether you have analogue modules for
safe, precise process workflow management
or software for simulation: user programs
must remain clear and manageable, despite
the expanding machine size and the increasing
level of automation on the machine.
Due to their function range, small controllers
such as Pnozmulti 2 contribute towards
safety while at the same time being
easy to use.
www.cpp-net.com
Online search: Pilz
AUTHOR:
ANDREAS VOLLAND
Product Manager,
Small Controllers
Pilz
cpp 02-2020 41