Rockwell Automation 1760-xxxx Pico GFX-70 Controllers User Manual - Manual (Page 150)

Publication 1760-UM002B-EN-P - March 2005
4-40 Wiring with Pico GFX-70
Analog Value Comparator/Threshold Value Switch
Pico GFX-70 provides 32 analog value comparators from A 01 to A 32.
With an analog value comparator or threshold value switch you can, for
example, compare analog input values with a set point value.
All Pico GFX-70 DC variants have analog inputs.
The following comparisons are possible:
• Function block input
>I1
greater than or equal to, equal to, less than or
equal to function block input
>I2
• Using the factors
>F1
and
>F2
as inputs enables you to amplify and
adjust the values of the function block inputs.
• The
>OS
function block input can be used as an offset for the
>I1
input.
• The
>HY
function block input is used for the positive and negative
switching hysteresis of the input
>I2
. The contact switches according to
the selected comparison mode of the function block.
ATTENTION
The function blocks are designed so that a function block
output can be assigned directly to the input of another
function block. This enables you always to have an
overview of which value is transferred.
If different data formats are used, such as if the first
function block uses 32 bits and an 8-bit or 16-bit format is
used for further processing, sign value errors or value
errors may occur when transferring from one function
block to another one.