Yokogawa Pneumatic Retractables RF20H - Manual (Page 5)

IM 12B06K07-E-E
2.2 Process integration
The control unit RF20C (EXmatic 460) is supplied
with 24V DC and with compressed air 4-6 bar. The
connection of the retractable fitting and the cleaning
and drain valves is realized by pneumatic hoses
which are gathered in a multi hose.
Figure 3: Process sequence
The respective status of the measuring unit
(alarm status, measuring status, cleaning status)
can be transmitted to a higher process control
system by means of contacts.
A cleaning cycle can be started via an external
trigger, e.g. from the pH transmitter.
The control unit RF20C (EXmatic 460) is a
completely independent control unit and can
principally be operated without any connection
to a transmitter or a process control system.
The control unit has a manual as well as an
automatic mode. The manual mode is for manually
triggering the movement of the retractable fitting
and the individual cleaning valves.
In automatic mode, a parameterized cleaning
process is run after starting a cleaning cycle.
After completion, the retractable fitting moves
to the measurement position.
Process Control System
Transmitter
Cleaning
solution
Drain
RF20C
(EXmatic 460)
24V DC
Air 4-6 bar