Siemens SENTRON PAC4200 Manual page 137

LIMIT LOGIC
Logical truth value resulting from the combination of up to 12 limit values "LIM0" to "LIM11",
taking account of the logical priority rules and allowing logical brackets.
The logic is represented on the display using the graphic symbols familiar from digital
technology.
Value "true": A violation has occurred
Value "false": No violation has occurred
Figure 9-13
LIM0, LIM1, ..., LIM11
Logic operations
SENTRON PAC4200
Manual, 09/2008, A5E02316180B-01
"LIMIT LOGIC" device settings
Limit values used to generate the logically combined limit
"LIMIT LOGIC".
9.2 Parameterizing the operator interface
A higher-level logic function block with four inputs
supplies the result of the logic operation "LIMIT
LOGIC".
Four logic function blocks, each with four inputs, are
connected to these four inputs.
Logic function block with four inputs. Supplies the
output value to the input of the higher-level logic
function block.
Each of the four inputs can be assigned:
• One of the twelve limit values LIM0 to LIM11
• One of the digital inputs I0.0 or I0.1
Six logic operations:
AND, OR, XOR and their negations NAND, NOR,
XNOR
AND
AND logic operation: The output value is only true if
all input values are true. The output value is false if
any one of the input values or several input values
are false.
Parameterizing
137