Chapter7 Online Module Change - Mitsubishi Melsec-Q Series User Manual

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ONLINE MODULE CHANGE
CHAPTER7
When changing a module online, carefully read the QCPU User's Manual (Hardware
Design, Maintenance and Inspection), "Online module change".
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/
(Note)
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ONLINE MODULE CHANGE
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 3.4.23, therefore, prerecord the data to be saved (Factory default
offset/gain value/User range settings offset/gain value/User range settings
thermal EMF offset/gain value (Un\G190 to Un\G253)).
(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 more than 50 times
after the first use of the product. (IEC 61131-2 compliant)
Failure to do so may cause malfunction.
(6) To satisfy with the accuracy, a warm-up (power distribution) period of 30
minutes is required after the online module change.
The dedicated instruction cannot be executed during an online module change. When
using the dedicated instruction to execute save/restoration, therefore, execute save/
restoration in the other system*.
If the other system is unavailable, execute restoration by performing write to the buffer
memory.
* : If the module is mounted on the remote I/O station, execute save/restoration in the other system
mounted on the main base unit. (Save/restoration cannot be executed in the other system mounted
on the remote I/O station.)