Mitsubishi Electric MELSEC FX3U - 19.4 FNC143 - UNI; 4-bit Linking of Word Data

560
FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
19 Data Operation 2 – FNC140 to FNC149
19.3 FNC142 – BTOW / BYTE to WORD
3) When "n" is an odd number, "00H" is stored in the high-order byte (8 bits) of the final one among the
combination result destination devices as shown below.
For example, when "n" is "5", the low-order byte (8 bits) of to +4 is stored in to
+2, and "00H" is stored in the high-order byte (8 bits) of +2.
4) When "n" is "0", the BTOW instruction is not executed.
Related instruction
Caution
Devices storing the combination source data may be equivalent to devices storing the combined data.
After combination, however, the high-order byte (8 bits) of the combination source data stored in the devices
used for the combination destination data is erased and overwritten with the data acquired by combining the
high-order byte (8 bits).
Errors
An operation error is caused in the following cases; The error flag M8067 turns ON, and the error code is
stored in D8067.
• When the combination source devices to +n-1 are outside the specified device range (error
code: K6706)
• When the combined data destination devices to +n/2 are outside the specified device range
(error code: K6706)
When "n" is an odd number, the number of a rounded up value decides the numer of devices. (error code:
K6706)
Instruction Description
WTOB (FNC141) Separates consecutive 16-bit data in byte units (8 bits).
S S D
D D
00H
b15 b8 b7 b0
S 
+0
+1
The high-order bytes is ignored.
+2
When
"n" is
"5"
D 
+0
+1
+2
34H
78H
12H
56H
9AH
ABH
CDH
ABH
12H
34H
78H
EFH 56H
CDH
9AH
+3
+4
When "n" is "5",
"00H" is stored.
b15 b8 b7 b0
EFH BCH
ABH
CDH
ABH
12H
34H
78H
EFH
56H
CDH
9AH
BCH
S 
=D11
D12
The high-order bytes is ignored.
When
"n" is
"6"
D 
=D10 34H
78H
12H
56H
9AH
It is not changed.
D13
D14
D15
CDH
EFH
ABH
56H
78H
9AH
D11
D12
D13
D14
D15
EFH BCH
D16
b15 b8 b7 b0 b15 b8 b7 b0
D16
Because these combination source devices are
also used for the combination destination, "ABH"
and "CDH" are erased and overwritten.
S S
D D