Mitsubishi Electric MELSEC iQ-R Series User Manual page 10

[Operating Precautions]
CAUTION
● When changing data and operating status, and modifying program of the running programmable
controller from an external device such as a personal computer connected to an intelligent function
module, read relevant manuals carefully and ensure the safety before operation. Incorrect change or
modification may cause system malfunction, damage to the machines, or accidents.
● Do not power off the programmable controller or reset the CPU module while the setting values in the
buffer memory are being written to the flash ROM in the module. Doing so will make the data in the
flash ROM and SD memory card undefined. The values need to be set in the buffer memory and
written to the flash ROM and SD memory card again. Doing so also may cause malfunction or failure
of the module.
● Note that when the reference axis speed is specified for interpolation operation, the speed of the
partner axis (2nd, 3rd, or 4th axis) may exceed the speed limit value.
● Do not go near the machine during test operations or during operations such as teaching. Doing so
may lead to injuries.
[Computer Connection Precautions]
CAUTION
● When connecting a personal computer to a module having a USB interface, observe the following
precautions as well as the instructions described in the manual for the personal computer used.
Failure to do so may cause the module to fail.
(1) When the personal computer is AC-powered
When the personal computer has a 3-pin AC plug or an AC plug with a grounding wire, connect
the plug to a grounding receptacle or ground the grounding wire. Ground the personal computer
and the module with a ground resistance of 100 ohms or less.
When the personal computer has a 2-pin AC plug without a grounding wire, connect the computer
to the module by following the procedure below. For power supplied to the personal computer and
the module, using the same power source is recommended.
1. Unplug the personal computer from the AC receptacle.
2. Check that the personal computer is unplugged. Then, connect the personal computer to the
module with a USB cable.
3. Plug the personal computer into the AC receptacle.
(2) When the personal computer is battery-powered
The personal computer can be connected to the module without taking specific measures.
For details, refer to the following.
Cautions When Using Mitsubishi Programmable Controllers or GOTs Connected to a Personal
Computer With the RS-232/USB Interface (FA-A-0298)
When the USB cable used is the GT09-C30USB-5P manufactured by Mitsubishi Electric, specific
measures are not required to connect the AC-powered personal computer to the module. However,
note that the signal ground (SG) is common for the module and its USB interface. Therefore, if an SG
potential difference occurs between the module and the connected devices, it causes failures of the
module and the connected devices.
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