Siemens 6AV2123-2JB03-0AX0 Retrofit HMI for KP700 Basic

Siemens 6AV2123-2JB03-0AX0 Retrofit-Compatible HMI for KP700 Basic Legacy Systems

The Siemens 6AV2123-2JB03-0AX0 is a 7-inch key panel HMI from the SIMATIC KP700 Basic series, designed for operator control and monitoring in machine-level automation environments. As legacy SIMATIC HMI panels reach end-of-life and spare parts become increasingly scarce, the 6AV2123-2JB03-0AX0 serves as a proven retrofit-compatible replacement for discontinued operator panels including the OP7, OP17, TP177, and earlier KP series units. NINERMAS maintains verified stock of this unit to support planned maintenance windows, emergency replacements, and long-term spare parts programs across processing, packaging, and discrete manufacturing industries.

This panel operates on 24 V DC supply and communicates via PROFINET and MPI/PROFIBUS interfaces, making it directly compatible with SIMATIC S7-300, S7-400, and S7-1200 controller platforms without requiring gateway hardware or protocol converters. Engineers replacing older TP177B or OP177B panels will find that the 6AV2123-2JB03-0AX0 supports WinCC Basic project migration with minimal screen rework, significantly reducing engineering hours during cutover.

Upgrade Compatibility Table

Retrofit Planning for Existing Automation Systems

A successful retrofit of the 6AV2123-2JB03-0AX0 into an existing control cabinet begins well before the physical swap. Engineers should first audit the existing control panel layout to confirm that the 192 × 138 mm cutout dimension is achievable within the cabinet door, and that the 46 mm mounting depth does not conflict with internal wiring ducts, terminal blocks, or the backplane of adjacent modules.

Power supply capacity is a critical early checkpoint. The 6AV2123-2JB03-0AX0 draws up to 4.5 W at 24 V DC. If the existing SITOP PSU8600 or SITOP modular power supply is already loaded near capacity due to additional I/O modules, signal isolators, or communication modules added since the original system design, a supplementary 24 V DC rail may be required. This is especially relevant in retrofit scenarios where a SIMATIC ET 200SP distributed I/O station or additional SM 321 digital input modules have been added to the rack since commissioning.

Terminal wiring for the 6AV2123-2JB03-0AX0 uses a standard 2-pin DC power connector. When replacing a TP177B or OP177B, the existing 24 V DC supply wiring can typically be reused directly, provided wire gauge and ferrule crimping meet current standards. The PROFINET RJ45 port replaces the older 9-pin Sub-D MPI connector found on legacy panels; if the controller is an S7-300 with only an MPI port on the CPU 315-2 DP, a CP 343-1 communication processor or an MPI-to-PROFINET gateway such as the PN/MPI Link will be required to bridge the protocol gap.

For systems still running on PROFIBUS DP, the 6AV2123-2JB03-0AX0 supports direct PROFIBUS connection via its integrated interface, allowing the existing DP cable and bus termination resistors to remain in place. Engineers should verify the PROFIBUS station address assigned to the legacy HMI and reassign the same address to the new panel during TIA Portal configuration to avoid address conflicts with other DP slaves such as SINAMICS G120 drives or ET 200M remote I/O stations on the same segment.

Project migration from WinCC flexible to WinCC Basic requires running the TIA Portal migration wizard. Most standard screen objects, alarm tags, and recipe structures migrate cleanly, but custom function keys, scripts, and VB-based logic blocks must be reviewed and rewritten manually. It is advisable to complete the migration and perform a full offline simulation before the scheduled maintenance window to identify any tag mapping discrepancies early. HMI screen layouts may require adjustment to accommodate the 7-inch widescreen aspect ratio of the 6AV2123-2JB03-0AX0 compared to the 5.7-inch 4:3 format of older panels.

Where the existing system includes a SIMATIC S7-1200 CPU 1214C or CPU 1215C controller, the 6AV2123-2JB03-0AX0 connects natively via PROFINET without any additional hardware, and the TIA Portal project can be configured entirely within a single engineering environment. This simplifies the overall retrofit scope and reduces the risk of communication configuration errors during commissioning.

Downtime Control During System Migration

Minimizing unplanned downtime is the primary concern for any HMI replacement on a live production line. NINERMAS recommends a structured pre-cutover preparation process to ensure the 6AV2123-2JB03-0AX0 is fully configured, tested, and ready before the maintenance window begins.

The first step is to create a complete backup of the existing HMI project using WinCC flexible or the legacy ProTool environment, and to archive the S7 program from the connected CPU using STEP 7 or TIA Portal. This protects the original control logic and operator screen configuration in the event that the cutover needs to be reversed. The CPU program itself does not need to be modified for the HMI replacement; only the HMI project and communication configuration require updating.

Pre-shipment functional testing is performed on every 6AV2123-2JB03-0AX0 unit dispatched by NINERMAS. Each panel is powered up, communication ports are verified, and display function is confirmed before packaging. This eliminates the risk of receiving a non-functional unit and discovering the fault only during the maintenance window, which is a common source of extended downtime in legacy spare parts procurement.

During the physical cutover, the recommended sequence is: power down the control cabinet, disconnect the legacy HMI panel, install the 6AV2123-2JB03-0AX0 into the prepared cutout, reconnect the 24 V DC supply and communication cables, power up the panel, download the migrated WinCC Basic project via Ethernet, and perform a live communication test with the PLC before resuming production. The entire physical swap and download process typically takes under 30 minutes when the project has been fully prepared and tested in advance.

For systems where continuous operation is critical, a parallel run strategy can be employed: the new 6AV2123-2JB03-0AX0 is configured and tested on a bench setup connected to a spare CPU or simulator before the production cutover, allowing operators to familiarise themselves with the new screen layout and alarm structure without production pressure.

Retrofit Support FAQ

Q1: Is the 6AV2123-2JB03-0AX0 a direct drop-in replacement for the TP177B 7″ or OP177B?
The 6AV2123-2JB03-0AX0 is functionally compatible as a replacement for the TP177B and OP177B in terms of power supply voltage and communication protocols. However, the panel cutout dimensions differ, and the engineering project must be migrated from WinCC flexible to WinCC Basic using the TIA Portal migration tool. Physical installation requires cutout verification and potential cabinet door modification.

Q2: Can this panel communicate directly with an S7-300 CPU via MPI without additional hardware?
The 6AV2123-2JB03-0AX0 does not have a native MPI port. For S7-300 CPUs without a PROFINET interface, a CP 343-1 Lean communication processor or an MPI/PROFIBUS-to-PROFINET gateway is required. For S7-300 CPUs with an integrated PROFINET port (e.g. CPU 315F-2 PN/DP), direct connection via PROFINET is supported without additional hardware.

Q3: What pre-shipment testing does NINERMAS perform on the 6AV2123-2JB03-0AX0?
Every unit undergoes power-on verification, display function check, and communication port inspection before dispatch. Units are shipped in original or equivalent protective packaging. A 12-month warranty is provided from the date of shipment, covering manufacturing defects and functional failures under normal operating conditions.

Q4: What is the typical lead time and stock availability?
NINERMAS maintains stock of the 6AV2123-2JB03-0AX0 to support urgent replacement requirements. Standard lead time for in-stock units is 3–7 business days for international shipment. For long-term spare parts programs requiring multiple units or scheduled delivery, contact sale@ninermas.com to discuss inventory reservation and supply agreements.