Honeywell EXCEL 5000 User Manual page 26

ALPHABETIC REFERENCE
Master controller
Cascade controller
Parameter Number
Descriptions
Cascade Operation
74-5577–33 (US)
EN2B-0184 GE51 R0518 (Europe)
Proportional band Xp
Number type: decimal, Unit: same as the controlled variable (X)
Default: 2.0, Range: 0 through 100.0
Proportional band value is equivalent to the throttling range.
Integral action time Tn
Number type: whole number, Unit: seconds
Default 1000 sec, Range: 0 through 7200 sec
If Integral action time is less than 15 seconds, integral control is disabled.
Minimum output
Number type: decimal, Unit: same as the cascade-controlled variable (XH)
Default: 0.0, Range: 0 through 100.0
Maximum output
Number type: decimal, Unit: same as the cascade-controlled variable (XH)
Default: 100.0, Range: 0 through 100.0
Proportional band Xp
Number type: decimal, Unit: same as the cascade-controlled variable (XH)
Default: 2.0, Range: 0 through 100.0
Proportional band value is equivalent to the throttling range.
Integral action time Tn
Number type: whole number, Unit: seconds
Default: 1000 sec, Range: 0 through 7200 sec
If Integral action time is less than 15 seconds, integral control is disabled.
Minimum output
Number type: decimal, Unit: percent
Default: 0.0 percent, Range: 0 through 100.0 percent
Maximum output
Number type: decimal, Unit: percent
Default: 100.0 percent, Range: 0 through 100.0 percent
P3 Xp (proportional band master controller)
P4 Tn (in seconds, integral action time of the master controller)
P5* Min (minimum limit of the cascade controller)
P6* Max (maximum limit of the cascade controller)
P7 Xp (proportional band of the cascade controller)
P8 Tn (in seconds, integral action time of the cascade controller)
P9 Min (minimum limit of the positioning signal, in percent)
P10 Max (maximum limit of the positioning signal, in percent)
P11 W (reference variable if entered as a parameter, not connected to a point)
Not for Excel Web / Excel Web II !
* Parameters P5 and P6 serve as the minimum and maximum limits,
respectively, of the setpoint assignment to the cascade controller.
As an example, the following diagram shows a master PID that is the room
temperature controller and a secondary PID that is the fresh air temperature
controller. The advantage of this arrangement is that the master controller and
secondary controller can each adapt to their own control sections.
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EXCEL CARE CONTROL ICONS