Analog Math Error Detection - Siemens LOGO! Manual

LOGO! functions
4.4 Special functions list - SF
4.4.31

Analog math error detection

Short description
The analog math error detection block sets an output if an error has occurred in the
referenced analog math function block (Page 209).
Symbol in LOGO!
Parameter MathBN
The value for the MathBN parameter references be the block number of an already-
programmed analog math function block.
Functional description
The analog math error detection block sets the output when the referenced analog math
function block has an error. You can program the function to set the output on a zero division
error, an overflow error, or when either type of error occurs.
If AutoRst is set, the output is reset prior to the next execution of the function block. If
AutoRst is not set, then whenever the output is set it remains set until the analog math error
detection block is reset with the R parameter. This way, even if the error subsequently
clears, the circuit program still has knowledge that an error did occur at some point.
In any scan cycle, if the referenced analog math function block executes before the analog
math error detection function block, the error is detected in the same scan cycle. if the
referenced analog math function block executes after the analog math error detection
function block, the error is detected in the next scan cycle
212
Wiring Description
Input En A change in the status from 0 to 1 at input En (Ena-
ble) enables the analog math error detection block.
Input R A signal at input R resets the output.
Parameter MathBN: block number of an analog math instruction
Err: ZD: Divide by 0 error
OF: Overflow error
ZD/OF: (Divide by 0 error) OR
(Overflow error)
AutoRst: Reset the output before the next execution
of the analog math error function block. Y = yes; N =
no
Output Q Q is set high if the error to detect occurred in the last
exectution referenced analog math function block
Manual, 10/2017, A5E01248535-AA
LOGO!