Online Module Change - Mitsubishi Electric Melsec Q Series User Manual

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ONLINE MODULE CHANGE

7 ONLINE MODULE CHANGE
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When performing an online module change, carefully read the following.
• QCPU User's Manual (Hardware Design, Maintenance and Inspection)
This chapter describes the specifications of an online module change.
(1) Perform an online module change by operating GX Developer.
(2) To ensure ease of offset/gain re-setting, there is a user range save/restoration
function that is performed by executing the dedicated instruction or read/write
from/to buffer memory.
POINT
(1) Perform an online module change after making sure that the system outside the
programmable controller will not malfunction.
(2) To prevent an electric shock and malfunction of operating modules, provide
means such as switches for powering off each of the external power supply and
external devices connected to the module to be replaced online.
(3) After the module has failed, data may not be saved properly. Referring to
Section 3.4.15, therefore, prerecord the data to be saved (offset/gain values of
Industrial shipment settings and User range settings in the buffer memory).
(4) It is recommended to perform an online module change in the actual system in
advance to ensure that it would not affect the other modules by checking the
following:
• Means of cutting off the connection to external devices and its configuration
are correct.
• Switching on/off does not bring any undesirable effect.
(5) Do not install/remove the module to/from the base unit, or the terminal block
to/from the module more than 50 times after the first use of the product. (IEC
61131-2 compliant)
Failure to do so may cause malfunction.
(Note)
Dedicated instructions cannot be executed during online module change. When
execution of a dedicated instruction is needed to save and restore data, execute it
1
using another system .
If no other system exists, restore the data by writing them to the buffer memory.
1: If the module is mounted on a remote I/O station, execute save/restoration on
another system connected to the main base unit. (Saving and restoration cannot
be executed by using a system connected to remote I/O station.)
MELSEC-Q
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