QJ71LP21 MELSEC-Q Series Redundant CPU Network Module - Mitsubishi Electric PLC Controller

QJ71LP21 module

Mitsubishi QJ71LP21

QJ71LP21 Profibus-DP

QJ71LP21

The Mitsubishi QJ71LP21 module is a Profibus-DP interface unit designed for industrial automation, enabling seamless communication between PLCs and Profibus-DP devices via high-speed data exchange.

Specification

SEODescription

The Mitsubishi QJ71LP21 module is a Profibus-DP communication interface designed for seamless integration into industrial automation systems. As a dedicated Profibus-DP master/slave module, it supports up to 125 directly connected slave devices via RS-485 communication, enabling high-speed data exchange at 12 Mbps. The QJ71LP21 operates within a 24 VDC voltage range (±10%) and functions reliably in temperatures from 0°C to 55°C. Featuring 32 digital input points and 32 digital output points for local I/O control, it also supports expansion through Mitsubishi's Q-series PLC modules. Widely used in manufacturing, automotive, and process industries, this module excels in real-time communication stability and protocol compliance. However, its configuration requires specialized software (GX Works), and compatibility is limited to Mitsubishi Q-series PLC platforms. The QJ71LP21 Profibus-DP interface remains a robust solution for distributed control systems despite its vendor-specific architecture.

SEOSpecification

Parameter	Specification
QJ71LP21 Module Type	Mitsubishi QJ71LP21 Profibus-DP Master Module
Communication Protocol	Profibus-DP (EN 50170)
Transmission Rate	9.6 kbps to 12 Mbps
Input Voltage	DC 5V ±5% (via base unit)
Operating Temperature	0°C to 55°C
Dimensions (WxHxD)	27.4 x 98 x 90 mm
Weight	0.2 kg
Mitsubishi QJ71LP21 Compatibility	Q Series PLC base units
Certification	CE, UL, cUL
QJ71LP21 Profibus-DP Nodes	Up to 125 stations supported

SEOQandA

question:Do you require advance payment before shipment?
answer:Yes, we require a deposit to confirm orders and ensure smooth processing.
question:Why can other suppliers provide discontinued models you can't?
answer:We only supply genuine new products; others may use old stock or refurbished units.
question:Do you offer technical selection support?
answer:Yes, we provide technical guidance to help choose suitable models for your needs.

SEOQandA_Product

question:How to resolve communication failure with QJ71LP21?
answer:Check Profibus cable connections, verify slave addresses, and ensure correct baud rate settings in GX Works parameters.
question:Why does QJ71LP21 not recognize connected slaves?
answer:Confirm GX Works configuration matches slave device settings, including correct GSD file import and data type alignment.
question:How to troubleshoot QJ71LP21 LED error indicators?
answer:Verify power supply, inspect module status via diagnostics in GX Works, and check for hardware faults or configuration mismatches.
question:Why is QJ71LP21 incompatible with a Profibus slave device?
answer:Ensure the slave device adheres to Profibus-DP standards and validate its GSD file compatibility with QJ71LP21 firmware version.
question:How to update QJ71LP21 firmware?
answer:Download the latest firmware from Mitsubishi's support site and use the MELSOFT Firmware Update Tool for installation.