Mitsubishi PLC MELSEC Q Series Communication Module QJ71EIP71

Overview

QJ71EIP71 is an EtherNet/IP network interface module. The core supports the EtherNet/IP protocol and is compatible with the CIP general industrial protocol. It can realize real-time I/O data communication and non-real-time message communication. It supports multiple Tag communication modes at the same time. For example, Class1 Tag communication can realize regular cyclic transmission of data. Class3 Tag communication completes communication through read and write requests. It adopts 10BASE-T/100BASE-TX interface. The data transmission speed is adaptive between 10-100Mbps and supports full-duplex/half-duplex mode. The maximum number of connected Tags for Class1 and Class3/UCMM Tag communication is both 256. The maximum amount of data sent and received by a single Tag is 722 words and 252 words respectively. The total data amount of all Tags can reach 32768 words, which can meet the data transmission requirements of parallel communication between multiple devices.

FAQ:

1.How to build the DLR ring network topology supported by QJ71EIP71? What is the time for ring redundancy switchover?

QJ71EIP71 DLR ring network topology construction steps:

1. Prepare Q series PLC and other DLR-compatible devices with this module (up to 50 nodes in a single ring), and prepare GX Works3 software and network cables.
2. Connect all nodes in series to form a linear link, leaving a disconnection point (to prevent broadcast storms).
3. Use the GX Works3 configuration module to be the DLR ring manager, assign the same subnet IP, set the 100Mbps full-duplex mode, and download parameters.
4. Connect the broken points to close the loop and verify node connectivity using software diagnostics or a ping test.

The DLR ring network redundancy switching time is less than 5ms, which can achieve faultless recovery without affecting real-time industrial data transmission.

2.How to configure the Class1 Tag communication of QJ71EIP71 through GX Works3 software to achieve real-time data interaction with third-party EtherNet/IP devices?

1. Hardware connection: QJ71EIP71 and the third-party EtherNet/IP device are connected to the same switch (one-to-one crossover cable), the power supply is normal, and the EDS file of the third-party device is obtained.
2. Software project creation: Create a new project and select matching CPU, add QJ71EIP71 in the module configuration, and record the I/O starting address.
3. Network parameters: Enter the module configuration interface, set the same subnet static IP, and enable the EtherNet/IP function.
4. Communication configuration: Import the EDS file, create a new Class1 connection, and match the producer/consumer roles of QJ71EIP71 and third-party devices.
5. Tag mapping: Define tags with the same name and length, turn on automatic refresh, and map to QCPU soft components (such as area D).
6. Download test: Download parameters, switch PLC to RUN mode, monitor Tag status, read and write soft components through GX Works3, and verify data synchronization.

3.How to set QJ71EIP71 to keep Tag communication uninterrupted when the CPU is shut down? What impact does this setting have on system stability?

1. Open GX Works3 and enter the EtherNet/IP function bar of the QJ71EIP71 parameter configuration interface.
2. Set the tag communication status when a CPU stop error occurs to “Continue communication”.
3. Check “Allow writing in RUN” and set the initial time to “Always OPEN wait”.
4. Download the parameters and restart the PLC for the settings to take effect.

Positive impact: Ensure data continuity of third-party devices and avoid data loss; support remote reading of fault logs to improve troubleshooting efficiency.

Negative impact: There is a risk of data inconsistency, which can easily cause equipment coordination disorder; increasing module load may lead to module failure; without interlocking, mechanical malfunction is prone to occur, posing safety risks.