The Logic Function Blocks - Mitsubishi Electric a2 Series Programming Manual

α
2 Simple Application Controllers
5.

The Logic Function Blocks

Logic Function Blocks operate by reading whether signals are ON or OFF and then setting the
status of their Outputs accordingly. There are six types of logic blocks available in the
Series - AND, OR, NAND, NOT, NOR, XOR. Analog signals cannot be processed by the Logic
blocks. In this chapter, each Function Block has a description, a diagram of the Function Block
as seen on the LCD Display, and a logic table to show how the Output is controlled by the input
signals.
Table 5.1: Boolean Logic function blocks
Logic
Block
State
AND
OR
NOT
XOR
NAND
NOR
Logic Block
Displayed
T h i s f u n c t i o n exe c u t e s l o g i c a l A N D
1 0 0
operation on given input signals. The input
O
2
signals connected should be of bit input
type only. 4 Bit input pins and 1 Bit output
3
pin. If all the inputs are ON then the output
4 A N D
is ON, otherwise output is OFF.
This function executes logical OR operation
1 0 0
on given input signals. The input signals
O
2
connected should be of bit input type only. 4
Bit input pins and 1 Bit output pin. If all the
3
i n p u t s a r e O F F t h e n o u t p u t i s O F F,
O R
4
otherwise output is ON.
0 0
This function executes logical NOT opera-
tion on given input signal. The input signal
O
1 connected should be of bit input type only. 1
Bit input pin and 1 Bit output pin. Output is
negation of Input given.
N T
This function executes logical XOR opera-
0 0
tion on given input signals. The input sig-
O
1
nals connected should be of bit input type
only. 2 Bit input pins and 1 Bit output pin.If
2
both the inputs are either OFF or ON then
X O R
out put is OFF, otherwise output is ON
This function executes logical NAND
1 0 0
operation on given input signals. The input
O
2
signals connected should be of bit input
type only. 4 Bit input pins and 1 Bit output
3
pin. If all the inputs are ON then output is
4 N A N D
OFF, otherwise output is ON
This function executes logical NOR
1 0 0
ation on given input signals. The input sig-
O
2
nals connected should be of bit input type
only. 4 Bit input pins and 1 Bit output pin. If
3
all the inputs are OFF then out put is ON,
N O R
4
otherwise output is OFF
Description
oper-
The Logic Function Blocks 5
Memory Section
Use Reference
19 Byte 5.1
19 Byte 5.2
10 Byte 5.3
13 Byte 5.4
19 Byte 5.5
19 Byte 5.6
5 - 1
α
2