User Manual_S7-1200 compressor controller
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3. Algorithm of the compressor operation
The compressor may be inactive (the compressor is not started when pressure drops below
the switching on pressure threshold)or active (the compressor is started when pressure
drops below the switching on pressure threshold). Activation of the compressor is carried out
in different ways depending on the selected operation mode. Below there are presented the
available operation modes including the ways of the compressor activation:
•
AUTOmode – the compressor activation requires pressing the START key (active
only in this mode)on the control panel (pressing the STOP key will deactivate the
compressor)
•
REM mode – the signal for the compressor activation is closing the external
potential-free contact connected to the compressor terminal block (the contact
opening results in the compressor deactivation)
•
CAL mode – the compressor activation and deactivation occurs according to the
setting calendar
•
NET mode - the compressor activation and deactivation occurs according to the
commands sent in the Modbus TCP protocol
The signal that causes the compressor to start and its loading is the signal from B3
transducer. Fig. 2 presents an example diagram of pressure changes in time with indicated
states of the compressor operation.
Fig. 2 Algorithm of the compressor operation.
The above diagram assumes that the compressor is active all the time. If the present
pressure (PA) drops below the switching on pressure threshold (PL),the compressor will
start and change from the stop state (0) to the compression state (2).
