Siemens 6AV6644-0AB01-2AX0 Replacement for MP 377 15″

Product Overview

Siemens 6AV6644-0AB01-2AX0 Replacement for MP 377 15″: Smooth Transition & Legacy System Compatibility

The Siemens 6AV6644-0AB01-2AX0 is a 15-inch WIDESCREEN Touch Multi Panel from the SIMATIC MP 377 series, designed for demanding industrial HMI applications across process automation, machine control, and plant visualization. As the MP 377 series approaches end-of-life and spare parts become increasingly scarce, many facilities running SIMATIC S7-300, S7-400, or legacy WinCC flexible projects are actively seeking a verified replacement or upgrade path that preserves existing wiring infrastructure, communication protocols, and operator familiarity.

TOPNLMS supplies the 6AV6644-0AB01-2AX0 as a direct replacement unit sourced from authorized channels, fully tested prior to shipment, and backed by a 12-month warranty. Whether your facility needs an emergency swap-out to minimize unplanned downtime or a planned migration to a modern SIMATIC HMI platform, our technical team can support the transition from initial assessment through commissioning.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful migration from a legacy MP 370 or TP 270 panel to the 6AV6644-0AB01-2AX0 rarely involves the HMI panel alone. In practice, field engineers typically address several interconnected components during the same maintenance window to ensure system stability and reduce future downtime risk.

On the communication side, the existing PROFIBUS DP cable and 9-pin Sub-D connector can typically be reused directly, as the MP 377 retains the same PROFIBUS interface pinout as its predecessors. If the site is transitioning to Ethernet-based communication, a SIMATIC NET CP 343-1 Ethernet module installed in the S7-300 rack enables PROFINET connectivity without replacing the PLC backplane or power supply module. For facilities still running MPI topology, the existing PC Adapter USB A2 (6ES7972-0CB20-0XA0) programming cable remains compatible for project download and online diagnostics.

On the control cabinet side, engineers often take the opportunity to inspect and replace aging SITOP PSU100S 24V DC power supply modules, which feed both the HMI panel and associated I/O racks. The MP 377’s 24 V DC input is directly compatible with standard SITOP output rails, requiring no rewiring of the power distribution block. If the cabinet houses a SIMATIC S7-300 CPU 315-2 DP or CPU 317-2 DP, the existing PROFIBUS network address and baud rate settings on the HMI project can be preserved without modification, significantly reducing commissioning time.

For facilities upgrading I/O infrastructure in parallel, SM 321 digital input modules and SM 322 digital output modules mounted on the existing S7-300 rack remain fully addressable from the new HMI without any changes to the PLC program’s symbol table or hardware configuration, provided the rack and slot assignments are unchanged. Where analog signal conditioning is involved, SM 331 analog input modules continue to operate transparently through the same PROFIBUS DP connection.

In applications where the MP 377 replaces a panel in a distributed architecture, ET 200S distributed I/O stations connected via PROFIBUS DP are fully visible to the new HMI through the existing S7-300 CPU, requiring no changes to the DP master configuration. This is particularly relevant in large process plants where I/O is distributed across multiple field cabinets connected to a central PLC rack.

Finally, for sites planning a longer-term migration toward TIA Portal and S7-1500, the 6AV6644-0AB01-2AX0 serves as a stable interim HMI that can be re-engineered into a SIMATIC Comfort Panel TP1500 Comfort (6AV2124-0QC02-0AX1) at a later stage, with WinCC Comfort supporting direct project import from WinCC flexible, preserving screen layouts, tag mappings, and alarm configurations.

Retrofit Guidance FAQ

Q: Can I reuse the existing PROFIBUS wiring when replacing an MP 370 with the 6AV6644-0AB01-2AX0?
A: Yes. The PROFIBUS DP interface on the MP 377 uses the same 9-pin Sub-D connector and supports the same baud rates (up to 12 Mbit/s) as the MP 370. No cable replacement is required. Verify the PROFIBUS address is set correctly in the HMI project before going online.

Q: Do I need to modify the WinCC flexible project when migrating from an MP 370 12″ to the MP 377 15″?
A: A resolution rescaling step is recommended since the display size and aspect ratio differ. WinCC flexible’s built-in migration wizard handles most screen object repositioning automatically. Manual review of alarm windows and trend displays is advised before final commissioning.

Q: Is the panel cutout the same as the MP 370?
A: No. The MP 377 15″ requires a panel cutout of 396 × 305 mm, which is larger than the MP 370 12″ cutout. Cabinet door modification or an adapter frame is typically required. Confirm available space in the control cabinet before ordering.

Q: Can the 6AV6644-0AB01-2AX0 communicate with an S7-1200 or S7-1500 PLC?
A: Direct MPI/PROFIBUS connection is not supported for S7-1200/1500. However, Ethernet communication via the HMI’s RJ45 port using the S7 Ethernet driver in WinCC flexible is supported, provided the PLC has an Ethernet interface. Confirm firmware compatibility with your specific CPU version.

Q: What programming cable is needed to download a project to the MP 377?
A: The PC Adapter USB (e.g., 6ES7972-0CB20-0XA0) via MPI, or a standard Ethernet cable via the RJ45 port using a direct IP connection in WinCC flexible. Ethernet download is generally faster and recommended for large projects.

Q: How long does commissioning typically take for a like-for-like replacement?
A: For a direct replacement with an existing WinCC flexible project and no wiring changes, on-site commissioning typically takes 2–4 hours, including project download, tag verification, and alarm testing. Allow additional time if screen rescaling or communication reconfiguration is required.

Warranty Assurance

Every 6AV6644-0AB01-2AX0 unit supplied by TOPNLMS undergoes a pre-shipment functional test covering display integrity, touch calibration, communication interface continuity, and power input verification. Units are shipped in anti-static protective packaging with full documentation.

• 12-Month Warranty: Covers all functional defects arising under normal operating conditions from the date of delivery.
• Pre-Shipment Testing: Each unit is powered on and tested for display, touch, and communication functionality before dispatch.
• Replacement Support: In the event of a warranty claim, TOPNLMS will arrange a replacement unit or repair at no additional cost, subject to fault verification.
• After-Sales Response: Technical support is available via email and phone within 1 business day for installation, commissioning, and compatibility queries.
• Procurement Assurance: All units are sourced from verified supply channels. Certificates of conformity and test reports are available upon request for quality-critical procurement processes.

For volume orders, lead time confirmation, or technical pre-sales consultation, contact our team directly.

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