96
CONTROL MODES
SP
Relay
Control
period
Deviation
On
Off
Control Low for HI510 base-dosing solution
75%
50%
25%
0%
100%
Figure 27:
Control Low with Relay On, Set Point & Deviation
Deviation
On
Off
Control High for HI510 acid-dosing solution
0%
Control
75%
50%
25%
Relay
100%
period
SP
Figure 28:
Control High with Relay On, Set Point & Deviation
Following graphs exemplify how the input parameters work.
Relay On time is proportional with Setpoint variance over Control period.
SP
Control period
Control mode
High
Control mode
Low
Deviation
Process value
Relay out
Relay out
On
On
Off
Off
Figure 29:
Proportional Control, Relay Out - Control Mode High/Low
