Azbil KFDB, User Manual

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1-6-5. Pneumatic Pressure Signal Receiver Unit
This unit operates either in a direct (local) made or in a remote (cascade) mode. In the former
case, this unit receives the pneumatic output signal (20 to 100 kPa {0.2 to 1.0 kgf/cm
2
}) of
the transmitter section and converts it into mechanical displacement which is fed via the
overtravel link to the deviation generating mechanism in order to be magnified to drive the
process variable (PV) pointer.
In the latter case, this unit receives an external pneumatic pressure setting signal (20 to 100
kPa {0.2 to 1.0 kgf/cm
2
}) and converts it into mechanical displacement which is fed via the
overtravel link to the deviation generating mechanism in order to drive the setpoint (SP)
pointer.
Fig. 1-11. Receiver Unit
1-6-6. Batch Switch Unit
This unit is used to prevent overswing (in the positive direction only) of a batch process when
it is initialized.
When the controller output pressure has exceeded a preset limit pressure (60 to 110 kPa {0.6
to 1.1 kgf/cm
2
}), the switch trips to suppress the output pressure to below the preset pressure.
preload pressure to the RES port of the controller.
Fig. 1-12. Batch Switch Unit