West Control Solutions N6600 - Manual (Page 22)

The offset process variable value is used for all PV-dependent functions (control,
display, alarm, recorder output etc.).
NOTE: This parameter value should be chosen with care. Any
adjustment to this parameter is, in effect, a calibration adjustment.
Injudicious application of values to this parameter could lead to the
displayed process variable value bearing no meaningful
relationship to the actual process variable value. There is no front
panel indication when this parameter is in effect (i.e. has been set to
a non-zero value).
The default value is 0.
3.2.3 Output Power 1
This parameter is the current Output 1 power level. It is a “Read Only” parameter
and is not adjustable.
3.2.4 Output Power 2
This parameter is the current Output 2 power level (if Output 2 is fitted). It is a
“Read Only” parameter and is not adjustable. If Output 2 is not fitted, this
parameter display is not applicable.
3.2.5 Proportional Band 1
This parameter is the portion of the input span of the Controller over which the
Output 1 power level is proportional to the displayed process variable value. It
may be adjusted in the range 0.0% (i.e. ON/OFF control) to 999.9%. The default
value of this parameter is 10.0%. The function of the Proportional Band 1 is
illustrated in Figure 3-1.
3.2.6 Proportional Band 2
This parameter is the portion of the input span of the Controller over which the
Output 2 power level is proportional to the displayed process variable value. It
may be adjusted in the range 0.0% (i.e. ON/OFF control) to 999.9%. The default
value of this parameter is 10.0%. This parameter is applicable only if Output 2 is
fitted. In Figure 3-1, Proportional Band 2 is shown (a) with a non-zero value (Case 1
and Case 2) - PID control, and (b) with a zero value (Case 3) - ON/OFF control.
3.2.7 Reset (Integral Time Constant)
This parameter is adjustable in the range 1 second to 99 minutes 59 seconds and
OFF (value greater than 99 minutes 59 seconds). This parameter is not applicable
if Proportional Band 1 (see Subsection 3.2.5) is set to 0 (ON/OFF control).
3-6 O075-3
PM-0075