Red Lion PCU - Manual (Page 29)

CONFIGURATION PARAMETER MODULES
Accessible from the unprotected parameter mode, the configuration
parameter modules allow the operator access to the controller’s fundamental
set-up parameters. There are nine possible configuration stages that can be
accessed. At the configuration stage access point “CNFP”, the operator uses
the UP & DOWN arrow buttons to select the desired configuration parameter
module. Press the PAR button to enter the module where the settings can be
viewed or modified. The PAR button is used to scroll through the parameters
and the UP and DOWN buttons are used to modify the parameter value. The
PAR button enters the desired choice, advancing to the next parameter. The
operator can press the DSP button to exit (escape) without modifying the
parameter. The unit returns to the normal display mode. After the parameters
in a module are viewed or modified, the unit returns to the configuration
access point, allowing access to other modules.
INPUT MODULE (1- IN)
T h e c o n t r o l l e r h a s s e v e r a l i n p u t s e t - u p p a r a m e t e r s t h a t m u s t b e
programmed prior to setting any other controller parameters.
Input Type (tYPE)
Select the signal input type Voltage (VOLt), or Current (Curr). The
appropriate signal input terminal for voltage is #8 and for current is #9.
Square Root Linearization (root) (Optional)
The main input can be linearized by use of the square root function. See
Square Root Linearization, page 35, for a complete description of the square
root function.
The “root” parameter in Program Module 1 applies to the main input, and the
“root” parameter in Program Module 7 applies to the Second Analog Input.
Decimal Point Position (dCPt)
Select the desired decimal point position for the scaled display. The
selected decimal point position appears in the following parameters; rnd,
dSP1, dSP2, SPLO, SPHI, SP, AL1, AL2, db-2, AHYS, and CHYS.
0
0.0
0.00
0.000
Rounding Increment ( rnd)
Rounding values other than “1” causes the scaled number to ‘round’ to the
nearest rounding increment selected (ie. rounding of ‘5’ cause ‘122’ to round
to ‘120’ and ‘123’ to round to ‘125’). If the process is inherently jittery, the
display value may be rounded to a higher value than “1”. If the range of the
process exceeds the required resolution, (ex. 0-1000 PSI, but only 10 PSI
resolution required), a rounding increment of 10 will effectively make the
display more stable.
This programming step is usually used in conjunction with programmable
digital filtering to help stabilize display readings (If display stability appears
to be a problem and the sacrifice in display resolution is unacceptable,
program higher levels of digital filtering or increase the level of process
dampening). Rounding increments of 10, 20, 50, and 100 may also be used to
add “dummy zeroes” to the scaled readings, as desired.
1
2
5
10
20
50
100
The rounding increment is for the controller’s display only and does not
affect (degrade) the control accuracy of the unit.
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