ABB PM573-ETH Replacement/Upgrade Solution for AC500

Product Overview

ABB PM573-ETH Replacement/Upgrade Solution for AC500: Smooth Migration from Legacy PLC Systems

The ABB PM573-ETH is a high-performance CPU module within ABB’s proven AC500 PLC platform, featuring an integrated Ethernet port for seamless connectivity in modern industrial control architectures. Whether you are replacing a failed unit, retiring an end-of-life controller, or executing a planned migration from an older ABB or third-party PLC system, the PM573-ETH delivers a reliable, specification-matched upgrade path with minimal disruption to your existing installation.

Engineered for demanding industrial environments, the PM573-ETH supports PROFINET, Modbus TCP, and EtherNet/IP communication protocols, making it compatible with a broad range of field devices, SCADA systems, and HMI panels already deployed in your facility. Its DIN-rail-mountable form factor and standard AC500 backplane interface allow direct installation into existing TB521, TB541, or TB561 terminal base units without mechanical modification to the control cabinet.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful migration to the PM573-ETH rarely involves the CPU alone. In practice, engineers upgrading from a PM554-TP or PM564-TP system will also evaluate the condition and compatibility of adjacent components. The TB521 and TB541 terminal base units that house the CPU module are typically reused without modification, as the PM573-ETH shares the same AC500 backplane connector pinout. If the existing terminal base shows signs of wear or contact oxidation after years of service, replacement with a new TB541 is straightforward and does not require rewiring the field terminals.

On the I/O side, the DC532 digital input/output modules and AI523 analog input modules connected via the CS31 field bus remain fully operational under the PM573-ETH. Engineers migrating from older systems that relied on Profibus DP communication can leverage the PM573-ETH’s built-in Ethernet port to transition field devices to Modbus TCP or PROFINET IO, often eliminating the need for a dedicated CM572-DP Profibus master module in the rack.

For facilities upgrading HMI panels alongside the CPU, the PM573-ETH’s Ethernet interface communicates natively with ABB CP600 series HMI panels and third-party SCADA systems via OPC-UA or Modbus TCP, removing the serial communication bottleneck common in older PM571-based installations. Where legacy serial links to CP430 or CP450 operator panels must be preserved during a phased migration, the PM573-ETH’s COM1 serial port maintains backward compatibility.

Power infrastructure is another consideration. The PS501-PROG programming cable and USB-to-serial adapter used with earlier AC500 CPUs remain compatible for initial commissioning and program upload. If the control cabinet’s 24 VDC power supply unit — such as an ABB CP-E 24/5.0 — is already sized for the existing CPU load, no power budget recalculation is required, as the PM573-ETH draws comparable current from the terminal base. For new installations or cabinet expansions, pairing the PM573-ETH with an ABB CP-E 24/10.0 power supply provides adequate headroom for additional I/O expansion modules.

Signal integrity during migration is preserved by retaining existing S500 I/O signal cables and terminal wiring. Where field signals pass through signal isolators or surge protection modules mounted on the DIN rail adjacent to the CPU rack, these devices are unaffected by the CPU swap and continue to protect analog and digital inputs from transient voltages common in motor drive and high-voltage switchgear environments.

Retrofit Guidance FAQ

Q: Can I reuse my existing wiring when replacing a PM572-ETH with the PM573-ETH?
Yes. The PM573-ETH uses the same TB521/TB541/TB561 terminal base. All field wiring connected to the terminal base remains untouched. Only the CPU module itself is swapped.

Q: Do I need to rewrite my IEC 61131-3 program?
No. Programs developed in PS501 Control Builder Plus for PM571/PM572/PM573 are directly compatible. Upload your existing project file to the PM573-ETH via USB or Ethernet without structural changes. Minor recompilation may be required to target the new CPU firmware version.

Q: Is the PM573-ETH compatible with my existing Modbus RTU field devices?
Yes. The PM573-ETH supports Modbus RTU via its serial COM port and Modbus TCP via Ethernet, allowing you to retain legacy serial field devices while adding Ethernet-connected devices in parallel.

Q: Will the PM573-ETH fit in my existing control cabinet without modification?
Yes. The PM573-ETH shares the standard AC500 CPU form factor and mounts directly onto the existing terminal base. No additional DIN rail space or cabinet cutout modification is required.

Q: How do I handle the transition from Profibus DP to Ethernet-based communication?
The PM573-ETH supports PROFINET IO natively over its Ethernet port. Profibus DP field devices can be integrated via a PROFINET-to-Profibus gateway during a phased migration, allowing you to upgrade the CPU immediately while transitioning field devices on a separate schedule.

Q: What is the recommended commissioning procedure after installation?
Power down the cabinet, remove the old CPU from the terminal base, insert the PM573-ETH, restore power, and upload the program via PS501 Control Builder Plus. Verify I/O mapping, communication node addresses, and Ethernet IP configuration before returning the system to production. Typical commissioning time for a like-for-like replacement is under two hours.

Warranty Assurance

Every ABB PM573-ETH unit supplied by TOPNLMS is covered by a 12-month warranty from the date of shipment. Prior to dispatch, each module undergoes functional verification including power-on self-test, communication port validation, and visual inspection for physical integrity. Units are shipped in anti-static packaging with appropriate cushioning to prevent transit damage.

In the event of a confirmed defect within the warranty period, TOPNLMS provides a direct replacement unit to minimize your system downtime. Our after-sales response team is reachable via email and phone to support fault diagnosis, RMA processing, and technical clarification. We maintain buffer stock of high-demand AC500 CPU modules to ensure replacement units can be dispatched within 1–3 business days.

For procurement teams, we issue a formal invoice, packing list, and test report with every shipment. Bulk orders and long-term supply agreements are supported with priority allocation and reserved stock arrangements. All units are sourced through verified supply channels and are accompanied by traceability documentation upon request.