Online Module Change - Mitsubishi Q64AD-GH User Manual

7 ONLINE MODULE CHANGE

7 ONLINE MODULE CHANGE
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When changing a module online, carefully read the QCPU User's Manual (Hardware
Design, Maintenance and Inspection), section 12.4.1 "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/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 PLC 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 (offset/gain values of
the 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 mount/remove the module onto/from base unit more than 50 times (IEC
61131-2-compliant), after the first use of the product.
Failure to do so may cause the module to malfunction due to poor contact of
connector.
(Note)
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.)
MELSEC-Q
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