Swann AMI Phosphate-II Operator's Manual page 77

AMI Phosphate-II
Program List and Explanations
Control
upwards/
downwards
5.3 Relay Contacts
5.3.1
A-96.250.641 / 290312
Setpoint: User-defined process value (Measured value or flow)
Range: 0–10 ppm
P-Band: Range below (upwards control) or above (downwards con-
trol) the set-point, within the dosing intensity is reduced from 100%
to 0% to reach the set-point without overshooting.
Reset time: The reset time is the time till the step response of a sin-
gle I-controller will reach the same value as it will be suddenly
reached by a P-controller.
Range: 0–9'000 sec
Derivative time: The derivative time is the time till the ramp re-
sponse of a single P-controller will reach the same value as it will
be suddenly reached by a D-controller.
Range: 0–9'000 sec
Control timeout: If a controller action (dosing intensity) is constantly
over 90% during a defined period of time and the process value
does not come closer to the setpoint, the dosing process will be
stopped for safety reasons.
Range: 0–720 min
Alarm Relay: The alarm relay is used as cumulative error indicator.
Under normal operating conditions the contact is open.
The contact closes upon:
 Power loss
 Detection of system faults like defective sensors or electron-
ic parts
 High case temperature
 Lack of reagents
 Process values out of programmed ranges.
Note: Above definition assumes that the alarm relay is used as
normally open (Terminals 10/11). If terminals 10/12 are used,
alarm relay normally closed, then the above definition is
inverted. See also
Phosphate-II, S.
Program alarm levels, hysteresis values and delay times for the fol-
lowing parameters:
Phosphate, Sample Flow or Case Temperature
The alarm values of Phosphate, Sample Flow and Case Tempera-
ture can be programmed in menu as well
Alarm Relay, S. 27
21.
and Connection Diagram
(5.3.1.2, S. 76).
75