Instruction Manual

Pointe Controller User Guide Appendix C: Ladder Diagram Block Reference
375
Configuration Reference
The parameters of this block are described in the following table:
Param Name Config Var Type Description
EN Enable no - The state of the rung (off/on)
received from the left.
ENO Enable
Out
no - The state of the rung (off/on)
passed to the right.
IN Input
Value
req real only*
Numeric
The input value. If a Numeric value
is manually entered, it must be real
/ floating.
OUT Output
Value
req real only* The result of calculating the
logarithm of the input value.
* Any 32-bit Real (F) Input, Output, or Memory tag. For more information, see “Defining Input,
Output, Memory tags” on page 114.
NOTE: This function cannot process a zero or negative input value. If the input
value is zero, then the value “1.#INF00” (infinite) is placed in the output. If the
input value is negative, then the value “- 1.#QNAN0” (not available) is placed in
the output. No error is generated.
C.3.15 Natural Logarithm (LN)
When used in a Ladder Diagram, the LN block finds the natural logarithm of an
input and sends the result to output.
Select the
tool (from the Math Blocks toolbar) and click on a ladder rung to
insert the following block:
Once the block is inserted, you can double-click on it to configure it.
Functional Description
This block always passes the Enable input state (EN) through to the Enable Out
output state (ENO) without change; when EN becomes on, ENO is turned on, and
when EN becomes off, ENO is turned off.
When EN becomes on, the block function is executed: the natural log of the Input
Value (IN) is calculated and the result is placed in the Output Value (OUT).