Mitsubishi MELSEC LJ71C24, Руководство пользователя

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9 DATA COMMUNICATION USING THE PREDEFINED PROTOCOL
(4) Length
Use this element when an element indicating the data length is included in a
packet.
y When sending: Calculates the data length of a specified range, and adds the
result to a send packet.
y When receiving: Verifies the data (setting value) corresponds to the length in
the receive data as the data length of a specified range.
The following table shows the items.
Item Description Remark
Element Name Set a name of the element. -
Code Type
Select a format of the data length.
ASCII Hexadecimal/ASCII Decimal/HEX
-
Data Length
Select the data length on the line.
The range is 1 to 4.
-
Forward Direction
(Upper Byte Lower Byte)
When sending: Sends a calculated length,
from the upper byte.
When receiving: Receives data, from the
upper byte.
Reverse Direction
(Lower Byte Upper Byte)
When sending: Sends a calculated length,
from the lower byte.
When receiving: Receives data, from the
lower byte.
Data Flow
Byte Swap (by Word)
When sending: Sends a calculated length
swapping the upper byte and
lower byte by word.
When receiving: Receives data swapping the
upper byte and lower byte by
word.
Not settable when
"Data Length" is 1
byte
Start
Set the starting element number of the calculating range.
The range is 1 to 32.
Calculating
Range
End
Set the ending element number of the calculating range.
The range is 1 to 32.
-