Contents

SAFETY PRECAUTIONS
CONDITIONS OF USE FOR THE PRODUCT
REVISIONS
INTRODUCTION
CONTENTS
ABOUT MANUALS
COMPLIANCE WITH THE EMC AND LOW VOLTAGE DIRECTIVES
THE MANUAL'S USE AND STRUCTURE
ABOUT THE GENERIC TERMS AND ABBREVIATIONS
DEFINITIONS AND DESCRIPTIONS OF TERMINOLOGY
DISCONTINUED MODELS
PRODUCT CONFIGURATION
1 OVERVIEW
- 1.1 Overview of the Serial Communication Module
- 1.2 Features of the Serial Communication Module
- 1.3 About Added/Changed Functions in Function Version B
2 SYSTEM CONFIGURATION AND AVAILABLE FUNCTIONS
- 2.1 Applicable Systems
- 2.2 Combinations of Programmable Controller CPU and External Device, and Available Functions
- 2.3 For Use in Multiple CPU System
- 2.4 Use with Basic Model QCPU
- 2.5 Use with Redundant CPUs
- 2.6 Use on MELSECNET/H Remote I/O Stations
- 2.7 Checking the Function Version, Serial No., and Software Version
3 SPECIFICATIONS
- 3.1 Performance Specifications
- 3.2 RS-232 Interface Specification
  - 3.2.1 RS-232 connector specifications
  - 3.2.2 RS-232 cable specification
- 3.3 RS-422/485 Interface Specifications
  - 3.3.1 RS-422/485 terminal block specifications
  - 3.3.2 RS-422/485 cable specifications
  - 3.3.3 Precautions when transferring data using RS-422/485 circuit
  - 3.3.4 Enabling or disabling echo back of the RS-422/485 interface
- 3.4 Serial Communication Module Function List
- 3.5 Dedicated Instruction List
- 3.6 Utility Package (GX Configurator-SC) Function List
- 3.7 List of GX Developer Setting Items for Serial Communication Modules
- 3.8 List of Input/Output Signals for the Programmable Controller CPU
- 3.9 List of Applications and Assignments of the Buffer Memory
4 SETTINGS AND PROCEDURES PRIOR TO OPERATION
- 4.1 Handling Precautions
- 4.2 Settings and Procedures Prior to Operation
- 4.3 Part Names and Functions
- 4.4 External Wiring
  - 4.4.1 Connecting the RS-232 interface (full-duplex communications)
  - 4.4.2 Connecting the RS-422/485 interface
- 4.5 Settings for GX Developer
  - 4.5.1 I/O assignment settings
  - 4.5.2 Switch settings for I/O and intelligent functional module
  - 4.5.3 The Intelligent function module interrupt pointer setting
- 4.6 Settings with the Utility Package (GX Configurator-SC)
- 4.7 Individual Station Test
  - 4.7.1 ROM/RAM/switch tests
  - 4.7.2 Individual station loopback test
- 4.8 Loopback Test
- 4.9 Maintenance and Inspection
  - 4.9.1 Maintenance and inspection
  - 4.9.2 When mounting/dismounting the module
5 DATA COMMUNICATION USING THE MELSEC COMMUNICATION PROTOCOL
- 5.1 Data Communication Functions
  - 5.1.1 Accessing the programmable controller CPUs using the MC protocol
  - 5.1.2 Message format and control procedure for data communication
  - 5.1.3 Programmable controller CPU setting for performing data communication
  - 5.1.4 Support of multiple CPU system or redundant system
  - 5.1.5 Support for the QCPU remote password function
- 5.2 Utilizing the MX Component
6 DATA COMMUNICATION USING THE NON PROCEDURE PROTOCOL
- 6.1 Data Reception from the External Device
  - 6.1.1 Receiving methods
  - 6.1.2 The receive area and the received data list
  - 6.1.3 Sequence program for data reception
  - 6.1.4 Receive data clear
  - 6.1.5 How to detect reception errors
  - 6.1.6 Received data count and receive complete code settings
- 6.2 Sending Data to the External Device
  - 6.2.1 Transmission methods
  - 6.2.2 Arrangement and contents of the transmission area and the transmission data
  - 6.2.3 Sequence program for transmission data
  - 6.2.4 How to detect transmission errors
- 6.3 Data Communications Precautions
7 DATA COMMUNICATION USING THE BIDIRECTIONAL PROTOCOL
- 7.1 Data Reception from the External Device
  - 7.1.1 Receiving methods
  - 7.1.2 Arrangement and contents of the receive area and the receive data
  - 7.1.3 Sequence program for data reception
  - 7.1.4 How to detect reception errors
  - 7.1.5 Receive data clear
- 7.2 Sending Data to the External Device
  - 7.2.1 Transmission methods
  - 7.2.2 Arrangement and contents of the transmission area and the transmission data
  - 7.2.3 Sequence program for data transmission
  - 7.2.4 How to detect transmission errors
- 7.3 Processing when Simultaneous Transmission Performed During Full-Duplex Communications
  - 7.3.1 Processing when simultaneous transmissions occur
  - 7.3.2 Communication data processing when simultaneous transmissions occur
- 7.4 Data Communications Precautions
8 DATA COMMUNICATION USING THE PRE-DEFINED PROTOCOL
- 8.1 Function of the Pre-Defined Protocol
  - 8.1.1 Data communication procedure
  - 8.1.2 Pre-defined protocol system setting
  - 8.1.3 Pre-defined protocol monitoring/test
  - 8.1.4 Protocol execution log storage function
  - 8.1.5 Executing Condition of Predefined Protocol Communication
  - 8.1.6 Programming Example
9 UTILITY PACKAGE (GX Configurator-SC)
- 9.1 Functions Available with Utility Package
- 9.2 Installing and Uninstalling the Utility Package
  - 9.2.1 Handling precautions
  - 9.2.2 Operating environment
- 9.3 Utility Package Operation
  - 9.3.1 Operation overview
  - 9.3.2 Starting the Intelligent function module utility
  - 9.3.3 Common utility package operations
- 9.4 System Registration to Flash ROM
  - 9.4.1 User frame registration
  - 9.4.2 Data for modem initialization registration
  - 9.4.3 Data for modem connection registration
  - 9.4.4 Modem function system setting/registration
  - 9.4.5 Transmission control and others system setting
  - 9.4.6 MC protocol system setting
  - 9.4.7 Non procedure system setting
  - 9.4.8 Bidirectional system setting
  - 9.4.9 Pre-defined protocol system setting
  - 9.4.10 Programmable controller CPU monitoring system setting
  - 9.4.11 Transmission user frame No. designation system setting
  - 9.4.12 Resetting the buffer memory/flash ROM setting values to the default values
  - 9.4.13 Flash ROM write allow/prohibit setting
- 9.5 Auto Refresh Setting
- 9.6 Monitor/Test
  - 9.6.1 X/Y monitor/test
  - 9.6.2 Modem function monitor/test
  - 9.6.3 Transmission control and others monitor/test
  - 9.6.4 MC protocol monitor
  - 9.6.5 Non procedure monitor/test
  - 9.6.6 Bidirectional monitor
  - 9.6.7 Pre-defined protocol monitor/test
  - 9.6.8 PLC CPU monitoring monitor
  - 9.6.9 Transmission user frame No. designation monitor
  - 9.6.10 Monitor/test others
  - 9.6.11 Display LED off and communication error information/error code initialization
- 9.7 Non Procedure Protocol Receive Data Clear
10 DEDICATED INSTRUCTIONS
- 10.1 Dedicated Instruction List and Available Devices
- 10.2 G(P).ONDEMAND
- 10.3 G(P).OUTPUT
- 10.4 G.INPUT
- 10.5 G(P).BIDOUT
- 10.6 G(P).BIDIN
- 10.7 G(P).CPRTCL
  - 10.7.1 Functional protocol
- 10.8 G(P).SPBUSY
- 10.9 ZP.CSET (Receive data clear)
11 TROUBLESHOOTING
- 11.1 Checking the Status of the Serial Communication Module
  - 11.1.1 Checking the LED ON status, communications error status, and switch setting status of the serial communication module
  - 11.1.2 Initializing error information of the serial communication module
  - 11.1.3 Reading the RS-232 control signal status
  - 11.1.4 Reading the data communication status (Transmission sequence status)
  - 11.1.5 Reading the switch setting status
  - 11.1.6 How to read the current operation status
  - 11.1.7 Clearing the programmable controller CPU information
- 11.2 Error Code Tables
  - 11.2.1 Error code table
  - 11.2.2 A compatible 1C frame communications error code table
  - 11.2.3 Error code list while modem function is used
- 11.3 Troubleshooting by Symptom
  - 11.3.1 The "RUN" LED is turned OFF.
  - 11.3.2 The "RD" LED does not blink even after message transmission from the external device.
  - 11.3.3 No response message is returned even though the external device transmitted a message and the "RD" LED blinked.
  - 11.3.4 Transmission request does not make the "SD" LED blink.
  - 11.3.5 Read request signal does not turn ON even though the external device transmitted a message and the "RD" LED was blinking.
  - 11.3.6 The CPRTCL instruction execution is not completed although the "RD" LED blinked.
  - 11.3.7 Communication error "NAK"
  - 11.3.8 Communication error "C/N"
  - 11.3.9 Communication error "P/S"
  - 11.3.10 Communication error "PRO."
  - 11.3.11 Communication error "SIO"
  - 11.3.12 Communication error "CH1 ERR." or "CH2 ERR."
  - 11.3.13 Communication is intermittent.
  - 11.3.14 Undecidable data are transmitted or received.
  - 11.3.15 Whether the communication error is caused on the Q series C24 or external device is unclear.
  - 11.3.16 Communication is not available via the modem.
  - 11.3.17 Communication is not available with the ISDN sub-address.
  - 11.3.18 Periodic transmission is not performed normally.
  - 11.3.19 Condition agreement transmission is not performed normally.
  - 11.3.20 Data cannot be received due to by an interrupt program.
  - 11.3.21 Data cannot be written to the flash ROM.
  - 11.3.22 Troubleshooting on the protocol setting data reading/writing
  - 11.3.23 The "ERR" LED is lit.
APPENDICES
- Appendix 1 Functional Improvements of the Q Series C24
  - Appendix 1.1 Comparison of Q series C24/GX Configurator-SC/GX Works2
  - Appendix 1.2 Precautions when updating the module from function version A to B
  - Appendix 1.3 Precautions when replacing the QJ71C24(-R2) with the QJ71C24N(-R2/R4)
- Appendix 2 QnA/A Series Module
  - Appendix 2.1 Functional comparison with the Q series C24 and the QnA/A series modules
  - Appendix 2.2 Using programs designed for the QC24 (N) and installing the Q series C24 into existing systems
    - Appendix 2.2.1 Using programs designed for the QC24 (N)
    - Appendix 2.2.2 Installing on existing systems
  - Appendix 2.3 Using programs designed for the computer link module and installing the Q series C24 into existing systems
    - Appendix 2.3.1 Using programs designed for the computer link module
    - Appendix 2.3.2 Installing the Q series C24 into existing systems
- Appendix 3 Processing Time
- Appendix 4 ASCII-Code Table
- Appendix 5 External Dimensions
- Appendix 6 Interfaces
  - Appendix 6.1 RS-232 interfaces used for the Q series C24
  - Appendix 6.2 Connection examples when using a converter
- Appendix 7 Communication Support Tool (MX Component)
  - Appendix 7.1 Overview of MX Component
  - Appendix 7.2 Usage procedure of MX Component
- Appendix 8 Example of Clear Process Program for Receive Data
- Appendix 9 Program Examples for Using Q Series C24 at MELSECNET/H Remote I/O Station
  - Appendix 9.1 System configuration and program conditions
  - Appendix 9.2 When accessing buffer memory using sequence program
  - Appendix 9.3 When sending on-demand data
  - Appendix 9.4 When receiving data using nonprocedural or bidirectional protocol
  - Appendix 9.5 When sending data using nonprocedural or bidirectional protocol
  - Appendix 9.6 When clearing received data
  - Appendix 9.7 When sending data using user frames
  - Appendix 9.8 When performing initial setting
  - Appendix 9.9 When registering user frame
  - Appendix 9.10 When reading user frame
  - Appendix 9.11 When deleting user frame
  - Appendix 9.12 When changing the communication protocol and transmission setting
- Appendix 10 Setting Value Recording Sheet
INDEX
WARRANTY

Mitsubishi Electric MELSEC Q QJ71C24N User's Manual

Mitsubishi Electric MELSEC Q QJ71C24N manual cover

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Mitsubishi Electric MELSEC Q QJ71C24N Specification

The Mitsubishi Electric MELSEC Q QJ71C24N is a high-performance communication module designed for integration within the MELSEC Q Series PLC systems. This module supports RS-232 and RS-422/485 communication protocols, enabling seamless connectivity with a wide range of industrial devices and systems. It is engineered to facilitate efficient data exchange in automation environments, where reliable communication is critical.

The QJ71C24N module features dual communication channels, each capable of operating independently, enhancing system flexibility and enabling simultaneous data processing. It supports various communication formats and speeds, providing adaptability to different application requirements. The module's compatibility with both point-to-point and multi-drop network configurations ensures its suitability for diverse communication topologies.

In terms of performance, the QJ71C24N offers a comprehensive set of diagnostic functions and error detection mechanisms, ensuring robust data integrity and facilitating troubleshooting. Its compact design aligns with the modular architecture of the MELSEC Q Series, allowing for easy installation and integration within existing systems.

The module is equipped with a user-friendly interface for configuration and monitoring, simplifying setup and maintenance tasks. It also supports a range of communication protocols, such as Modbus and Mitsubishi’s own MC Protocol, broadening its application scope in industrial automation.

Overall, the Mitsubishi Electric MELSEC Q QJ71C24N is a versatile and reliable communication module that enhances the data handling capabilities of the MELSEC Q Series PLCs, making it a valuable component in complex and demanding industrial environments.

Mitsubishi Electric MELSEC Q QJ71C24N F.A.Q.

What is the primary function of the QJ71C24N module in a MELSEC Q-Series PLC system?

The QJ71C24N module is a communication module used in the MELSEC Q-Series PLC system for serial communication. It supports both RS-232 and RS-422/485 communication protocols, allowing the PLC to communicate with serial devices such as barcode readers, printers, or other PLCs.

How do you configure the baud rate for the QJ71C24N module?

To configure the baud rate for the QJ71C24N module, you need to use the GX Works2 software. Access the parameter settings for the QJ71C24N module, select the desired channel, and then set the baud rate under the communication settings. Make sure to download the updated parameters to the PLC.

What are common troubleshooting steps if the QJ71C24N module is not communicating with connected devices?

Common troubleshooting steps include: 1) Checking the physical connections and cables for defects, 2) Verifying that the communication settings (baud rate, parity, stop bits) match between the module and the device, 3) Ensuring the correct protocol is selected, and 4) Using diagnostic tools in GX Works2 to check for error codes and logs.

Can the QJ71C24N module be used for Modbus communication, and if so, how is it set up?

Yes, the QJ71C24N module can be used for Modbus communication. It requires configuring the module for Modbus RTU or ASCII mode using GX Works2. You must also set up the correct communication parameters and use the appropriate Modbus addresses and function codes for communication.

What maintenance practices are recommended to ensure the longevity of the QJ71C24N module?

Recommended maintenance practices include: Regularly checking and securing all cable connections, keeping the module free of dust and debris, periodically updating the firmware and software for improved performance and security, and monitoring the module's operation through diagnostic tools to preemptively address any issues.

How can you update the firmware on a QJ71C24N module?

To update the firmware on a QJ71C24N module, download the latest firmware from the Mitsubishi Electric official website. Connect to the PLC using GX Works2, and use the firmware update tool to upload and install the new firmware version onto the module. Ensure that the PLC is in a safe state before starting the update process.

What should you do if the QJ71C24N module is overheating?

If the QJ71C24N module is overheating, ensure that it is installed in a well-ventilated area with adequate clearance around it. Check for any blockages in the ventilation slots, and consider adding additional cooling solutions like fans or heat sinks if necessary. Also, verify that the module is not overloaded beyond its specifications.

Are there any specific environmental conditions that should be avoided to ensure optimal performance of the QJ71C24N module?

Yes, the QJ71C24N module should be kept away from extreme temperatures, high humidity, corrosive environments, and exposure to direct sunlight. It should also be protected from strong vibrations and electromagnetic interference to ensure optimal performance and longevity.

How do you perform a loopback test on the QJ71C24N module to verify communication functionality?

To perform a loopback test on the QJ71C24N module, connect the transmit and receive pins of the communication port together. Then, send data from the PLC and verify if it receives the same data back. This test helps confirm that the communication port is functioning correctly.

What steps should be followed to backup the configuration settings of the QJ71C24N module?

To backup the configuration settings of the QJ71C24N module, use GX Works2 to upload the current configuration from the PLC to your computer. Save the settings file in a secure location for future reference or restoration. Regular backups are advised whenever configuration changes are made.