Mitsubishi Electric MELSEC FX3U Programming Manual page 706

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
2. 32-bit operation (DBAND and DBANDP)
Depending on how the input value (32-bit binary value) specified by [
band range between [
The output value is controlled as shown below:
Command
input
In the case of "Lower limit value > Input value" ...............Input value −
In the case of "Upper limit value < Input value" ..............Input value −
In the case of "Lower limit value ≤ Input value ≤ Upper limit value" ................................ 0 → Output value
Output value
Caution
• When the output value overflows, it is handled as follows:
- In the 16-bit operation
The output value is a 16-bit binary value with sign. Accordingly, if the operation result is outside the
range from -32768 to +32767, it is handled as follows:
Lower limit value of dead band
Input value
- In the 32-bit operation
The output value is a 32-bit binary value with sign. Accordingly, if the operation result is outside the
range from -2,147,483,648 to +2,147,483,647, it is handled as follows:
Lower limit value of dead band [
Input value [
Error
An operation error is caused when the instruction is executed in the setting status shown below; The error flag
M8067 turns ON, and the error code (K6706) is stored in D8067.
16-bit operation
32-bit operation
704
+1, ] and [
S S
1 1
FNC257
S S
1 2
DBAND
S
S
1 S
1
+1, 3 +1,
S S
S
2 +1, 2 +1,
3
S S
S
1 3
1 +1, +1,
Input
value
S
1 = 10
S
= -32768
3
S
1
S S
3 +1, 3 ] = -2,147,483,648
Relationship
>
S S
1 2
] > [
[ +1,
S S S
1 1 2
+1, ], the output value [
S S
2 2
S
D
3
S S S
3 3 +1, 3
S S
S
3 +1, 3
3
S
S S
3
2 +1, 2
Output
value
Lower limit value of
dead band
[ S
S
1
1 +1,
Output
Output value = 0
Output value = -32768-10
= 8000H-AH
= 7FF6H
= 32758
S
+1, 1 ] = 1000
+1, ]
S
2
29 Data Table Operation – FNC250 to FNC269
29.2 FNC257 – BAND / Dead Band Control
+1, ] compares to the dead
S S
3 3
+1,
D
S S D
+1, 1
1
Lower limit value → Output value
S S
D
2 +1, 2
Upper limit value → Output value
D
[ D D ]
+1,
] Output
Input value
[ S
3
Upper limit value of
dead band [
S
+1,
2
Output value = -2,147,483,648-1000
= 80000000H-000003E8H
= 7FFFFC18H
= 2,147,482,648
] is controlled.
D
D
+1,
D
+1,
D
+1,
]
S
+1,
3
]
S
2