ABB AX410 User Manual page 47

Single and Dual Input Analyzers for Low Level Conductivity
AX410, AX411, AX413, AX416, AX418, AX450, AX455 & AX456
Output Type
set to
Pulse
60
Pulses/Minute
PID Controller
IM/AX4CO Issue 11
Pulse Frequency Ouput
The pulse frequency output is the number of relay pulses per minute required for 100%
control output. The Pulse Frequency Output is interrelated to the chemical reagent
strength and the solution flow rate. The chemical reagent flowrate and pulse frequency
is adjusted experimentally to ensure that the chemical reagent is adequate to control
the dosing under maximum loading. Adjust the Pulse Frequency Output in Manual
Mode and set to 100% valve output before setting up the PID parameters.
For example, if the observed value on the display is 6 and the control point is 5 then the
frequency needs to be increased.
The actual number of pulses per minute is calculated using the following equation:
Actual pulses per minute =
Set the pulse frequency between 1 and 120 pulses per minute in 1 pulse per minute
increments.
Control
Output
0
25
50
75
100
Note. If the pulse frequency of 120 is reached then concentration of the reagent needs
to be increased.
Note. Changes to the pulse frequency do not take effect until the start of a new cycle.
Output = 0%
Output = 50%
Output = 100%
See Section 5.8.2.
Power Recovery
See Section 5.9.
CONFIG. SECURITY
% control output x pulse frequency output
Pulse Frequency Output/Minute
1 10 50
0 0 0
0.25 2.5 12.5
0.50 5.0 25
0.75 7.5 37.5
1.00 10.0 50
Permanently de-energized
Energized
0.3s
De-energized
Energized
0.9s
0.3s
De-energized
Examples. Pulse Frequency =
50 pulses per minute (1 pulse every 1.25s)
5 PROGRAMMING
100
120
0
30
60
90
120
2.1s
0.3s 0.9s
45