3.35 Programmable Logic (Function Groups LOGIC and LOG_2)
Programmable (or user-configurable) logic enables the user to link binary signals
within a framework of Boolean equations.
Two function groups for programmable logic are available, that can be used
independently of each other. There are only two differences between these two
function groups:
●
LOGIC offers 32 logical equations.
LOG_2 offers only 4 logical equations.
●
On the other hand, LOG_2 features long-term timers.
For example for output 1:
o
LOGIC: Time t1 output 1 and LOGIC: Time t2 output 1: settable
from 0 to 600 s.
o
LOG_2: Time t1 output 1 and LOG_2: Time t2 output 1: settable
from 0 to 60,000 s.
The following description concentrates on the function group LOGIC. Where
applicable, any differences to LOG_2 are mentioned.
Binary signals in the P634 may be linked by logical “OR” or “AND” operations
with the option of additional NOT operations by setting LOGIC: Fct.assignm.
outp. 1 (or LOGIC: Fct.assignm. outp. 2 to LOGIC: Fct.assignm. outp.
32, or LOG_2: Fct.assignm. outp. 1 to LOG_2: Fct.assignm. outp. 4).
The Boolean equations need to be defined without the use of brackets. The
following rule applies to the operators: “NOT” before “AND” before “OR”.
A maximum of 32 elements can be processed in one Boolean equation. In
addition to the signals generated by the P634, initial conditions for governing the
equations can be set using setting parameters, through binary signal inputs, or
through the serial interfaces.
Logical operations of the function group LOGIC can be controlled through the
binary signal inputs in different ways.
The binary input signals LOGIC: Input 01 EXT (or LOGIC: Input 02 EXT, …,
LOGIC: Input 40 EXT) have an updating function, whereas the input signals
LOGIC: Set 1 EXT (or LOGIC: Set 2 EXT, …, LOGIC: Set 8 EXT) are
latched. The logic can only be controlled from the binary signal inputs configured
for LOGIC: Set 1 EXT if the corresponding reset input LOGIC: Reset 1 EXT)
has been configured for a binary signal input. If only one or neither of the two
functions is configured, then this is interpreted as “Logic externally set”. If the
input signals of the two binary signal inputs are implausible (such as when they
both have a logic value of “1”), then the last plausible state remains stored in
memory. (For LOG_2, there are no such parameters for assigning binary input
signals.)
3 Operation
P634
P634/EN M/R-42-A // P634‑311‑653 3-219