Blocks And Block Numbers; Logic Operations - Siemens Logo! Manual

Programming LOGO!

3.3 Blocks and block numbers

This chapter shows you how to use LOGO! elements to
create complex circuits and how blocks and I/O are inter-
connected.
In Chapter 3.4 we are going to show you how to transform
a conventional circuit to obtain a LOGO! circuit program.
Blocks
A block in LOGO! represents a function that is used to con-
vert input information into output information. Previously
you had to wire the individual elements in a control cabinet
or terminal box.
When you create the circuit program, you interconnect the
blocks. To do so, simply select the connection you require
from the Co menu The menu name Co is an abbreviation
of the term "Connector".

Logic operations

The most elementary blocks are the logic operations:
S
AND
S
OR
S
...
I1
I2
x
x
These special functions offer you significantly higher perfor-
mance:
S
Pulse relay
S
Up/down counter
S
On-delay
S
Softkey
S
....
In Chapter 4 you will find a full list of the LOGO! functions.
60
Inputs I1 and I2 are here connected
1
to the OR block. The last two inputs
of the block remain unused and are
Q
identified by the creator of the circuit
program with an 'x'.
LOGO! Manual
A5E00380835-01