PRO-FACE ST400 ST401 membrane

PRO-FACE ST400 / ST401 Membrane Keypad — Product Overview

The PRO-FACE ST400 and ST401 are legacy 3.8-inch monochrome HMI (Human Machine Interface) operator panels manufactured by Digital Electronics Corporation of Japan, now part of Schneider Electric. These compact, cost-effective programmable operator interfaces feature 320 × 240 QVGA resolution and were widely deployed in industrial automation, PLC-based control systems, and factory equipment monitoring applications across manufacturing sectors worldwide.

The ST400 model communicates via RS-422 serial interface, while the ST401 uses RS-232C. Both units feature LED backlighting, six physical function keys, and touch panel operation — supporting 8 × 6 keys per screen with one or two-point touch capability. These HMI units have reached end-of-sale status (2012/09/28), making replacement spare parts increasingly critical for maintaining existing installations.

Why Choose PRO-FACE Technology?

• Japanese Precision Engineering: Digital Electronics Corporation, founded in 1969, is a pioneer in industrial HMI technology, now part of Schneider Electric — a global leader in energy management and industrial automation with over 100,000 employees worldwide.

• Proven Reliability: The ST Series HMI panels have been deployed in demanding industrial environments for decades, with a documented track record in factory automation, packaging machinery, and process control applications.

• Full Compatibility: This replacement membrane is specifically designed for both ST400 (RS-422) and ST401 (RS-232C) models — no modifications required for installation.

• Factory-Quality Replacement: Manufactured to exact specifications of the original PRO-FACE membrane keypad, ensuring proper fit, sealing, and tactile response for reliable long-term operation.

Technical Specifications

Typical Applications

• Industrial Automation: PLC-based control and monitoring systems in manufacturing plants

• Factory Equipment Control: Operator interfaces for CNC machines, packaging equipment, and assembly lines

• Process Control: Chemical processing, food & beverage, and pharmaceutical manufacturing

• Legacy System Maintenance: Critical replacement part for aging PRO-FACE ST Series HMI units no longer in production

• Building Automation: HVAC control panels and energy management systems

Quality Assurance and Support

• ✓ Original Replacement Part: Factory-grade membrane keypad specifically designed for PRO-FACE ST400 and ST401 HMI units

• ✓ Professional Technical Support: 15+ years engineering team experienced in industrial HMI repair and spare parts sourcing

• ✓ Quality Inspection: All products are tested before shipment to ensure proper tactile response and electrical compatibility

• ✓ Fast Shipping: Ships within 1-3 business days from Hong Kong warehouse

• ✓ 30-Day Returns: Hassle-free return policy for unused items

• ✓ 1-Year Warranty: Manufacturer warranty included for peace of mind

Packing and Shipping

Each membrane keypad is carefully packaged with anti-static materials and protective cushioning to ensure safe delivery. All shipments are carefully wrapped and quality-checked before dispatch. For international orders, buyers are responsible for any applicable customs duties and taxes. Remote area surcharges may apply for certain destinations — contact us for details before ordering.