14
4-2 Field description
4-2-1 Data field
Standard frame
Option frame
All data except partial special data are treated with 16 bits length. In the data field of communication frame, data
use hexadecimal notation (0000
H
– FFFF
H
) and each figure is expressed with ASCII code. Further, in case of
negative integer data (data with sign), minus data are produced by taking the two's complement.
In the standard frame, 1 byte of a special adding data is provided in addition to 4 bytes of the data field, and
minus ('–') is set only when communicating negative data exceeding 16 bits length (output frequency of M09 and
M35 in reverse rotation).
Note:
- Make all A – F of hexadecimal capital letters.
- When polling, send with setting zero ('0') in all data field of the request frame.
- When selecting, the data field of the ACK response field becomes indefinite.
Example) When setting 108.5 Hz in the function S01 (frequency command) (maximum frequency: 120 Hz).
1) Calculate setting value according to the data format of S01 (20,000/max. frequency)
Data = 108.5Hz
×±
20,000/120Hz (
＋
in forward rotation, – in reverse rotation
）
=
±
18083.3
≅
±
18083
2
）
Convert the data to hexadecimal (If the data is negative, take the two's complement).
Data = 18083
･････････････････
(in forward rotation)
= 46A3
H
Data = -18083
････････････････
(in reverse rotation)
= 0-18083
＝
65536-18083
＝
47453
= B95D
H
3
）
Set data.
Position
Setting value
(Forward)
Setting value
(Reverse)
1st character of data ASCII '4' ASCII 'B'
2nd character of data ASCII '6' ASCII '9'
3rd character of data ASCII 'A' ASCII '5'
4th character of data ASCII '3' ASCII 'D'
4-2-2 Check sum field
These data are to check for error in the communication frame when transmitting data. The calculation method is
to express the data in ASCII code, which data are the lowest 1 byte of the sum of every 1 byte in the data field
except SOH and check sum.
Example) When the added result is 0123
H
Position Setting value
Check sum 1 ASCII '2'
Check sum 2 ASCII '3'
Special added data
8 9 10 11 12
1st character 2nd character 3rd character 4th character
5 6 7 8
1st character 2nd character 3rdt character 4th character
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