Hach-Lange SI794 D tr User Manual - Manual (Page 78)

P controller
Application in integrating systems
(e.g. closed tank, batch processes).
PI controller
Application in non-integrating systems
(e.g. aeration basin).
PID controller
The additional derivative action compensates for
measurement peaks.
Controller characteristic
Controller functions
PID controller
Setpoint
+100
-100
O
2
Neutral zone Y
p
=0
Note:
In Hold mode the controller output acts as configured
(Y = const. or Y = 0).
Proportional
action Y
P
[%] Relay 1
Relay 2
78