Attention

IronPLC implements many parts of the IEC 61131-3 standard and is working toward full Structured Text support. Key features still missing include arrays and structures. Try it out in the IronPLC Playground.

LN

Returns the natural logarithm of a numeric input.

IEC 61131-3

Section 2.5.1.5.2

Support

Supported

Signatures

#

Input (IN)

Return Type

Support

1

REAL

REAL

Supported

2

LREAL

LREAL

Supported

Description

Returns the natural logarithm (base e) of IN. The input must be positive; the result of LN applied to zero or a negative value is undefined.

Example

See Also

  • LOG — base-10 logarithm

  • EXP — natural exponential