Function Blocks; Chapter Overview; General Rules; Block Inputs - ABB ACS800 Application Manual

Function blocks

Chapter overview

The chapter describes the function blocks.

General rules

The use of input I1 is compulsory (it must not be left unconnected). Use of input
I2, I3, etc. is voluntary for the most blocks. As a rule of thumb, a unconnected input
does not affect the output of the block.

Block inputs

The blocks use three input formats:
• integer
• boolean
• text string
The used format varies depending on the block. For example, the ADD block uses
integer inputs and the OR block boolean inputs. Text string format is used only by the
EVENT block.
Note: The inputs of the block are read when the execution of the block starts, not
simultaneously for all blocks!
13
Function blocks