MelsecQ - Hardware Setup
- Last UpdatedAug 04, 2025
- 3 minute read
Apart from 100BASE-TX, 10BASE-T, 10BASE5, or 10BASE2 Ethernet cabling, no special hardware setup is required for a Plant SCADA interface.
Note: MelsecQ devices support an AutoUDP port (port 5001) that opens when a module is initialized with an IP address. Using this port for SCADA communications is not recommended, as other applications may attempt to access the same device via the AutoUDP port.
Plant SCADA Computer Setup
You should set up your specific Ethernet card as required and confirm basic network communications before proceeding with the communications configuration for the MelsecQ driver. Refer to your hardware documentation for instructions.
To set up the MelsecQ software
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Open Mitsubishi GX Developer, and then double-click Network parameters to display the dialog box.
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Click MELSECNET/Ethernet . The Ethernet Operations dialog box appears.
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Enter the parameters in the module listbox.
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Click Operational Settings .
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Enter the IP address .
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Click End .
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Save and write data to the PLC.
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Manually reboot the PLC to reset the program memory.
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Choose Ethernet Diagnostics on the Diagnostics menu to check that IP address is correct. The Ethernet diagnosis dialog box should look like this:
Use the following screenshot of the Mistubishi GX Developer to help you set up the PLC and Ethernet module. After entering your settings, the dialog boxes should look like this:
AJ71QE71-B5, A1SJ71QE71-B2 and A1SJ71QE71-B5 Hardware
The B2 has a Coax cable connector for 10Base2 and the B5 has an AUI connector for 10Base5 type connections. Mitsubishi recommend using a Transceiver with SQETEST of HeartBeat functionality if using the B5 model.
There are no switches on the Ethernet module models QJ71E71-100, QJ71E71 and QJ71E71-B2. Configuration is performed via the Mitsubishi GX Developer PLC software.
Indicators on the front of the module
|
LED name (QJ71E71-100) |
LED name (QJ71E71-B5, QJ71E71-B2) |
Display Description |
LED is on |
LED is off |
|
RUN |
RUN |
Normal operation display |
Normal |
Abnormal |
|
INIT |
INIT |
Initial processing status display |
Normal completion |
Not processed |
|
OPEN |
OPEN |
Open processing status display |
Normally opened connection available |
Normally opened connection not available |
|
SD |
SD |
Data sending display |
Data being sent |
Data is not sent |
|
ERR |
ERR |
Setting abnormal display |
ERR. ERR. Abnormal |
Normal setting |
|
COM.ERR. |
COM.ERR. |
Communication abnormal display |
Communication abnormal occurrence |
Normal communication in progress |
|
100 M |
(Not used) |
Transmission speed display |
100Mbps |
10Mbps/When not connected |
|
RD |
RD |
Data receiving status display |
Data being received |
Data not received |
The [OPEN] LED turns on/off depending on the open states of user connections 1 to 16.
(The open states of the system connections, for example, automatic open UDP port are not included.)
The [ERR.] LED turns on in the following cases:
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When setting values in GX Developer (mode, station number, and/or network number) are incorrect.
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When an error has occurred in the Ethernet module or PLC CPU and the operation is disabled due to the error.