Siemens 6AV6545-0BB15-2AX0 Replacement for SIMATIC HMI OP 73

Product Overview

Siemens 6AV6545-0BB15-2AX0 Replacement for SIMATIC HMI OP 73: Seamless Transition from Legacy Operator Panels

The Siemens 6AV6545-0BB15-2AX0 is a SIMATIC HMI OP 73 operator panel designed for human-machine interface applications in industrial control environments. As Siemens progressively phases out legacy OP-series panels in favor of newer SIMATIC HMI Basic and Comfort Panel lines, many facilities running S7-300, S7-400, or even older S5-series PLCs are facing urgent replacement decisions. TOPNLMS maintains verified stock of the 6AV6545-0BB15-2AX0 to support exactly these migration and emergency-replacement scenarios — minimizing downtime and preserving existing control-system investments.

Whether your plant is running a SIMATIC S7-315-2 DP CPU with a legacy OP 73 panel on a PROFIBUS DP network, or you are mid-project upgrading a distributed I/O cabinet that still relies on the original OP 73 form factor, this unit provides a direct physical and electrical replacement path. The 6AV6545-0BB15-2AX0 retains the same 3.8-inch STN monochrome display, 24 VDC supply input, and PROFIBUS DP interface that field engineers have relied on for years — meaning your existing panel cutout, DIN-rail mounting bracket, and cable harness remain fully compatible without modification.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful OP 73 replacement rarely involves the panel alone. In most retrofit projects, the 6AV6545-0BB15-2AX0 is installed alongside a broader set of control-system components that must be verified or simultaneously upgraded to ensure system integrity.

On the controller side, facilities running a Siemens CPU 315-2 DP (6ES7315-2AH14-0AB0) or a CPU 314C-2 DP (6ES7314-6CH04-0AB0) will find that the OP 73 communicates natively over PROFIBUS DP without any gateway or protocol converter. If the existing PROFIBUS cable and PROFIBUS DP connector (6ES7972-0BB52-0XA0) are in good condition, they can be reused directly — simply terminate the bus correctly at both ends and verify the DP address assignment in WinCC flexible matches the replacement panel’s configured station address.

For installations where the control cabinet also houses a Siemens ET 200S distributed I/O head station (6ES7151-1BA02-0AB0) or a SM 321 digital input module (6ES7321-1BH02-0AA0), the OP 73 replacement does not affect I/O mapping or PLC program logic — the panel is a pure visualization device and its swap-out is transparent to the CPU scan cycle. This makes the 6AV6545-0BB15-2AX0 one of the lowest-risk components to replace during a planned maintenance window.

Power supply compatibility is equally straightforward. If the cabinet uses a Siemens SITOP PSU100S 24V/10A (6EP1334-2BA20) or equivalent 24 VDC regulated rail, the OP 73 draws approximately 0.25 A at 24 VDC — well within the headroom of any standard SITOP unit. No additional fusing or wiring changes are required.

For projects that are simultaneously migrating from ProTool to WinCC flexible, the existing OP 73 project file can be imported and converted using the WinCC flexible Migration Wizard. If the migration also involves upgrading the CPU to a Siemens S7-1200 (6ES7214-1AG40-0XB0) or S7-1500 CPU 1511-1 PN (6ES7511-1AK02-0AB0), note that these newer controllers use PROFINET rather than PROFIBUS DP, and a PROFIBUS DP/PROFINET gateway (6GK1411-2AB10) or a panel upgrade to the KTP700 Basic PN series would be the recommended long-term path. However, for sites that must maintain PROFIBUS DP infrastructure in the near term, the 6AV6545-0BB15-2AX0 remains the correct and cost-effective interim solution.

In multi-panel installations, it is common to replace several OP 73 units across a production line simultaneously. TOPNLMS can supply matched batches with consistent firmware revisions to simplify commissioning and spare-parts management.

Retrofit Guidance FAQ

Q: Can I reuse my existing PROFIBUS DP cable and connector?
A: Yes. The 6AV6545-0BB15-2AX0 uses a standard 9-pin Sub-D PROFIBUS DP port. As long as the existing cable is correctly shielded and terminated, and the bus termination resistors are properly set at both ends of the segment, no cable changes are required. Verify the DP station address in WinCC flexible matches the address set on the replacement panel.

Q: Do I need to reprogram the PLC after replacing the OP 73?
A: No. The OP 73 is a visualization device only. The PLC program, data blocks, and I/O configuration are unaffected by the panel replacement. You only need to download the existing WinCC flexible project to the new panel using a standard PC/MPI adapter or PROFIBUS programming cable.

Q: Will the replacement panel fit the existing cabinet cutout?
A: Yes. The 6AV6545-0BB15-2AX0 shares the same physical dimensions and panel cutout requirements as all OP 73 variants. The front-panel gasket for IP65 sealing is included. No cabinet modification or additional hardware is needed.

Q: Is the WinCC flexible project from the old panel compatible with this unit?
A: Yes. Projects created in WinCC flexible 2008 (including SP1 through SP5) are directly transferable to the 6AV6545-0BB15-2AX0. If your project was originally created in ProTool, use the WinCC flexible Migration Wizard to convert it before downloading.

Q: What communication protocols does this panel support?
A: The 6AV6545-0BB15-2AX0 supports PROFIBUS DP as its primary communication interface. It is compatible with Siemens S7-200, S7-300, and S7-400 PLCs, as well as S5 controllers via a suitable protocol adapter. It does not natively support PROFINET or Ethernet — for those requirements, consider the KTP series panels.

Q: Can this unit be used as a spare/standby replacement in a critical production environment?
A: Yes. TOPNLMS recommends holding at least one spare 6AV6545-0BB15-2AX0 per production line where OP 73 panels are in service. Each unit is tested before shipment and ships with a 12-month warranty, making it suitable for critical-spare inventory programs.

Warranty Assurance

Every Siemens 6AV6545-0BB15-2AX0 shipped by TOPNLMS is covered by a 12-month warranty from the date of delivery. Prior to shipment, each unit undergoes functional verification including power-on testing, display check, and communication port inspection. Units that do not pass our outbound quality check are not shipped.

In the event of a warranty claim, TOPNLMS provides replacement support with a target response time of 1–2 business days. Defective units returned within the warranty period will be replaced at no additional cost, subject to inspection confirming the defect is not caused by mishandling, incorrect wiring, or installation outside the specified operating conditions.

For procurement teams managing critical-spare programs, TOPNLMS can provide batch test reports, serial number records, and shipping documentation (commercial invoice, packing list, and certificate of origin) to support customs clearance and internal asset-management requirements. Lead times for in-stock units are typically 3–7 business days for international shipments via DHL Express or FedEx International Priority.

For volume orders, framework agreements, or technical pre-sales consultation, contact our team directly.