Instruction Manual

Appendix C: Ladder Diagram Block Reference Pointe Controller User Guide
374
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 signed only*
T_DONE
T_VALUE
T_PREVAL
Numeric
The input value.
OUT Output
Value
req signed only* The result of calculating the
absolute value of the input value.
* Any Input, Output, or Memory tag labeled as “signed. For more information, see “Defining Input,
Output, Memory tags” on page 114.
C.3.14 Logarithm (LOG)
When used in a Ladder Diagram, the LOG block finds the base-10 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 logarithm of the Input
Value (IN) is calculated and the result is placed in the Output Value (OUT).
The block function is executed every time the ladder is scanned, so long as EN
remains on. If EN becomes off, then OUT remains at its last calculated value until
EN becomes on and the block function is executed again.