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MELSEC-Q
1 OVERVIEW
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1 OVERVIEW
This manual describes the specifications for the QJ71C24N, QJ71C24N-R2,
QJ71C24N-R4, QJ71C24, QJ71C24-R2 serial communication module (hereinafter
referred to as "Q series C24"), as well as the procedures prior to starting the operation,
maintenance, inspection, data communication methods for use with external devices
and troubleshooting.
When applying the following program examples to the actual system, make sure to
examine the applicability and confirm that it will not cause system control problems.
1.1 Overview of the Serial Communication Module
The Q series C24 is a module that connects the Q series PLC CPU and an external
device using an RS-232 or RS-422/485 line for serial communication, in order to
achieve the data communication described below.
By using a modem/terminal adapter, a public line (analog/digital) can be used for data
communication with a remote location.
• PLC data collection/change from the external devices
(See the MELSEC Communication Protocol Reference Manual.)
• PLC monitoring and control from the external devices (See Chapter 2 of the User's
Manual (Application).)
• Data receiving and sending in any formats that conform to the external device
specifications (See (2) and (3) of Section 1.2.)
• Collection of measured data from a measuring device (See (2) of Section 1.2.)
• Operation of a PLC CPU that is connected to a personal computer (hereinafter
abbreviated as PC) installed with GX Developer (SW4D5C-GPPW-E or later,
hereinafter abbreviated as GX Developer). (See the GX Developer Manual.)
QJ71C24-R2
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• PLC data collection/change
• PLC monitoring and control from an
external device
• Data receiving and sending in any
formats that conform to the external
device specifications
• GX Developer
• File writing/reading
• Device monitoring/testing
• Collection of measured
data
• Collection of read data
Being a convenient means of connection among different devices (PCs, display
devices, printers, etc.), the serial communication line is the most widely used
medium on the market today.