YOKOGAWA EXA DO402G, User Manual

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<5. Parameter setting>
5-21
IM 12J05D02-01E
- Adjustable parameters:
Cleaning time or washing time (tw) Recovery time after washing (tr)
Interval time for wash cycle.
The graph shows a typical response curve during washing. The wash and
recovery times need to be set to suit the process.
Fault alarm: Contact S4 by default set to function as an alarm, indicating that the EXA
has found a fault in the measuring loop. If the self diagnostics of the EXA
indicate a fault or error, the FAIL contact will be switched. In most cases
this will be caused by a malfunction of the measuring loop.
The FAIL contact is also closed when the power is removed.
The “FAIL” contact may also be configured as a fourth process alarm.
100
50
0
ton toff
50% 50%
% duty cycle control
Duty cycle
ton > 0.1 sec
Duty cycle
toff > 0.1 sec
Duty cycle
Proportional
Range
DO
% of output range
Time
Setpoint
Figure 1 Duty cycle control
100
50
0
% controller output
Proportional
Range
0.3 s
Maximum pulse frequency
50% pulse frequency
No pulses
0.3 s
DO
% of output range
Time
Setpoint
Figure 2 Pulse Frequency control
9th Edition: Aug. 05, 2015-00