Message Formats And Control Procedures Of Qna Compatible 4C Frame - Mitsubishi MELSEC Q Series Reference Manual

3.1.5 Message formats and control procedures of QnA compatible 4C frame

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3 WHEN COMMUNICATING USING THE QnA COMPATIBLE 3E/3C/4C FRAMES OR 4E FRAME
This section explains the control procedures and message formats of each protocol
format when data communication is performed using QnA compatible 4C frame for the
C24.
The section shown in the message explanation diagram of this section corresponds
to the portion of the message explanation diagrams indicated in sections 3.3.2 and
after of this chapter.
Refer to Section 3.1.6 regarding the content of data in the
specification method.
For the following items, refer to the sections listed below:
• How to read the MC protocol control procedure : Section 3.1.1
• Basic formats for data communication
POINT
It shows the form 1 to 5 ((1) to (5)) for the QnA compatible 4C frame shown in this
chapter.
(a) The sum check code is added only when sum check is enabled. When sum
check is disabled, the sum check code is not added.
(b) When sum check is enabled, the sum check is performed only for the
characters in the areas indicated by an asterisk ( ) in the diagrams (1) to (4).
When transmitting (diagram (5)) by a binary code, the sum check is
performed only for the data (excluding "10
indicated by an asterisk ( ), and is sent after converting to the ASCII code.
(c) The contents of "Character area A", "Character area B" and "Character area
C" in the diagrams (1) to (5) depend on the processing contents. Refer to the
description of each command for more information. The contents of each
character area are the same for all four formats.
(d) The time from the command message reception to the response message
transmission by a module can be set between 0 ms to 150 ms. (set by GX
Works2 or GX Configurator-SC)
(e) When "10 " data is included in the areas marked with an asterisk ( ) in the
H
diagram (5), "10
the data is sent. (The data is sent as "10
However, the added "10
sent.
(f) Control procedure formats 3 and 5 cannot be used when data communication
is performed in a system configured with an m:n connection between the
external devices and the programmable controller CPUs.
" (DLE code) is added immediately in front of the data before
H
" is not included in the "Number of data bytes" to be
H
section and data
: Section 3.1.4
" added by (e) below) in the area
H
" "10 " + "10 ".)
H H H
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