Control Techniques Digitax ST - Page 160

Menu 12
Parameter
structure
Keypad and
display
Parameter x.00
Parameter
description format
Advanced parameter
descriptions
Serial comms
protocol
Electronic
nameplate
Performance
160 Digitax ST Advanced User Guide
www.controltechniques.com Issue Number: 1
The variable selectors allow two source values (defined by Pr 12.08, Pr 12.28 and Pr 12.09, Pr 12.29) to be combined as defined by the mode
(Pr 12.10, Pr 12.30) to produce an output (Pr 12.12, Pr 12.32) which can be routed to the destination parameter (defined by Pr 12.11, Pr 12.31). The
actions of the variable selector are defined by the mode parameter as given below. If the mode parameter is changed or the variable selector is
disabled because neither source is routed to a valid parameter all the internal state variables (i.e. time constant accumulator, etc.) within the selector
are reset. When the Sectional control mode is selected the function is also reset, and the output is held at zero, when the control (Pr 12.15 or
Pr 12.35) is zero. It is active when the control has a non-zero value.
12.14 Variable selector 1 source 2 scaling
12.34 Variable selector 2 source 2 scaling
Coding
Bit SP FI DE Txt VM DP ND RA NC NV PT US RW BU PS
311
Range ±4.000
Default 1.000
Update rate 4ms x number of menu 9 or 12 functions active read
12.15 Variable selector 1 control
12.35 Variable selector 2 control
Coding
Bit SP FI DE Txt VM DP ND RA NC NV PT US RW BU PS
2 111
Range 0.00 to 100.00
Default 0.00
Update rate Background
Mode value Action Result
0 Select input 1 output = input1
1 Select input 2 output = input2
2 Add output = input1 + input2
3 Subtract output = input1 - input 2
4 Multiply output = (input1 x input2) / 100.0
5 Divide output = (input1 x 100.0) / input2
6 Time constant output = input1 / ((control param)s + 1)
7 Linear ramp
output = input1 via a ramp with a ramp time of (control
param) seconds from 0 to 100%
8 Modulus output = | input1 |
9 Powers
control = 0.02: output = input1
2
/ 100.0
control = 0.03: output = input1
3
/ 100.0
2
control has any other value: output = input1
10 Sectional control
control = 0.00: disabled, accumulator reset and output
zero control <> 0.00: output as defined below
11
External rectifier
monitor
See below.