M - 12
Example 6: For Write Command of three bytes
data registers: In order to modify or
configure, users must send two write commands to accomplish this task. First one only
change register’s 2 Low Order Bytes (LB)and is just similar to the previous example ,
However second command must write on converted register of original one to write or
modify value of High Order Byte (HB)(as example below illustrate How to set decimal
point and sign of value for detail description of Sign & Decimal Point configuration, refer to
Table 10.26 of Communication).
Following Table illustrates how to convert the register:
Format
Register
Register
(Hex. Number)
Register
(Binary Number)
Method: change MSB of
character 0 of Register to 1
hh MSB x x x x x x x
Reg. of SP1 value 01 0000 0001
Example:
Converted SP1 value:
81
1000 0001
Table 8.3: Conversion Method of 3 Bytes Register for Write Function.
Lets examine how to write SP1 with different values: +1000 and –100.0:
Send / Response Command string format:
Value +1000:
DATA
Desired
Values:
+1000
DEVICE
ADDRESS
FUNCTION
CODE
06
REGISTER
DATA VALUE
(2 bytes used)
CRC
1
st
command
(for absolute
value)
1 BYTE
01
1BYTE
06
HB
00
LB
01
HB
03
LB
E8
LB
D8
HB
B4
2
nd
command
(for Sign &
dec.point)
1 BYTE
01
1BYTE
06
HB
00
LB
81
HB
00
LB
10
LB
D8
HB
2E
Figure 8.4: Write (3 Data bytes) Commands Sample via
Infinity Configuration Software.