Mitsubishi MELSEC LJ71C24, Руководство пользователя

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9 DATA COMMUNICATION USING THE PREDEFINED PROTOCOL
(8) Non-verified Reception
Use this element when receive data include data not needed.
The C24 skips characters as many as the specified number if a receive packet
includes a Non-verified reception.
The following table lists the items.
Item Description Remark
Element Name Set a name of the element. -
0
(variable number of characters)
Set this item when the number of
characters not to be verified varies in
each of communication.
Data Length
1 to 2048
(specified number of characters) Set the number of characters not to be
verified.
-
POINT
y When "Data Length" is '0', the following requirements need to be met.
(1) Only one Non-verified reception can be placed in a packet.
(2) Include a Non-verified reception in the calculating range of a Length.
Otherwise, place any of the following data immediate after a Non-verified
reception.
Static Data
Terminator
Check code + Static Data
Check code + Terminator
(3) Two or more of the following four elements cannot be placed in the same
packet.
Conversion variable (Variable number of data)
Conversion variable (Fixed number of data and Variable number of digits)
(Excluding a case where "Number of Data" is '1' and "Delimiter" is not "No
Delimiter".)
Non-conversion variable (Variable length)
Non-verified reception (Variable number of characters)
y In receive packet data from other devices, the C24 needs to be able to
discriminate data corresponding to a Non-verified reception from those of a
Terminator or a Static Data following a Non-verified reception.
(Example)
When value of a Terminator or value of a Static Data following a Non-verified
reception is used in a Non-verified reception, the C24 recognizes it as data of a
Terminator or a Static Data following a Non-verified reception and perform the
verify/receive process.