Siemens SIMATIC S7-1500R/H Getting Started page 10

Principle of operation
Controlling the speed of the fans and controlling the traffic lights and barriers
Every fan:
● has two speeds (stages), which are switched on or off depending on the measured
pollutant concentration.
● has 2 directions of rotation. Depending on whether pollution is measured, the fan must
blow or suck.
The H-CPU measures the pollutant concentrations in the tunnel via analog input modules
and air-quality sensors.
If the pollutant concentration exceeds the maximum limit, the H-CPU responds in ET 200SP
via digital output modules as follows:
● It increases the speed of the fan motors
● It switches the traffic light system to red after two minutes
● It closes the barriers after two minutes
If the pollutant concentration falls below an average limit, the H-CPU responds in ET 200SP
via digital output modules as follows:
● It switches the ventilation motors to stop
● It switches the traffic lights to green
● It opens the barriers
Controlling the lighting in the tunnel
The H-CPU measures the light intensity outside and inside the tunnel using analog input
modules. Depending on the outdoor light, digital output modules adjust the brightness of the
entry lights in the tunnel to the optimum vision conditions. The digital output modules also
control the interior lights in the tunnel, depending on the day / night time.
The user program in the CPU specifies limits and controls the input and output modules of
the ET 200SP.
The Comfort Panels visualize the S7-1500H redundant system in an HMI screen. If required,
the operator can switch to manual operation via the HMI screen and change limit values.
S7-1500R/H redundant system
Getting Started, 10/2018, A5E44910930-AA
Introduction to the example
1.2 Structure and task of the example
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