Rockwell Automation 1772-L8_LW_LWP_LX_LXP,D17726.5.8 User Manual - Manual (Page 167)

Data Manipulatuion and
Comparison Instructions
Chapter 12
12-12
The Get Byte instruction addresses either the upper or lower byte of a data
table word. A 1 is entered after the word address for an upper byte; a 0 is
entered for the lower byte.
There are two ways to perform a Get Byte/Put instruction.
Case 1. One Get Byte
XXXD 040
ZZZ
B
YYY
8
PUT
ZZZZ
16
only these three letters
are displayed
The Get Byte instruction is programmed in the condition area of the ladder
rung. It tells the processor to make a duplicate of all 8 bits in the addressed
byte. When the rung containing the Get Byte/Put instructions goes true,
the data is transferred to both the upper and lower byte of the word address
of the Put instruction.
Case 2. Two Get Bytes
XXXD 040
BCC
B
WWW
8
PUT
BBCCC
16
only these three letters
are displayed
XXXD
B
YYY
8
XXX word address
WWW
YYY
octal values Ć upper or lower byte
D
0
1
Ć lower byte
Ć upper byte
Two Get Byte instructions are programmed in the condition area of the
ladder rung. It tells the processor to make a duplicate of all 8 bits in each
addressed byte. When the rung containing the Get Byte/Put instructions
goes true, the data from the first get byte is transferred into the upper byte
of the addressed Put instruction. Also, the data from the second get byte is
transferred into the lower byte of the addressed Put instruction.
Keystrokes
Enter a Get Byte/Put instruction by performing the following steps.
1. Press -[B]-.
2. Enter <address>.
3. Enter <byte designation>.
Important: Repeat steps 1, 2 and 3 when using two Get
Byte instructions.