Schneider Electric 172PNN26022 Replacement for Momentum Series

Product Overview

Schneider Electric 172PNN26022 Replacement for Momentum Series: Smooth Migration & Legacy System Upgrade

The Schneider Electric 172PNN26022 is a Modbus Plus Network Adaptor designed for the Momentum Series distributed I/O and control platform. As industrial facilities face end-of-life notices on legacy Schneider Momentum infrastructure, sourcing a verified, tested replacement for the 172PNN26022 has become a critical procurement priority. TOPNLMS supplies this module from stock with full functional testing, a 12-month warranty, and rapid international dispatch — enabling your engineering team to execute a controlled migration with minimal unplanned downtime.

The Momentum platform was widely deployed across process industries, water treatment, building automation, and discrete manufacturing throughout the 1990s and 2000s. Many sites still operate Momentum I/O bases, adaptor modules, and Modbus Plus backbones as part of a larger Modicon Quantum or Modicon Premium control architecture. When the 172PNN26022 network adaptor fails or reaches end-of-support, the entire I/O island it serves can go offline — making fast, like-for-like replacement the lowest-risk path before a full system migration is planned and budgeted.

This module slots directly into the Momentum I/O base, connecting the local I/O assembly to the Modbus Plus network segment. It communicates with the host PLC — typically a Modicon Quantum 140CPU controller or a Modicon Premium TSX57 processor — via the Modbus Plus peer-to-peer token-passing protocol at 1 Mbit/s. No re-engineering of the network topology, no changes to the PLC program’s I/O mapping, and no rewiring of the field terminal blocks are required when replacing a failed 172PNN26022 with a tested unit of the same reference.

Compatibility Comparison Table

Seamless Upgrade Solutions: Migration-Ready Components

A controlled migration away from an aging Momentum Modbus Plus segment rarely involves replacing a single module in isolation. Engineering teams typically audit the full I/O island and communication backbone before committing to a replacement strategy. The following components are commonly evaluated alongside the 172PNN26022 during a Momentum system review:

When the Modbus Plus trunk cable or drop cable shows degradation — a common cause of intermittent communication faults that are misdiagnosed as adaptor failure — the Modbus Plus SA85 ISA card or PCMCIA card used at the engineering workstation for network diagnostics is often the first tool deployed. Verifying network health with a known-good diagnostic interface before swapping the 172PNN26022 can save significant troubleshooting time on site.

For sites running mixed I/O types on the same Momentum base, the 170ADI34000 (16-channel discrete input) and 170ADO34000 (16-channel discrete output) I/O modules are frequently stocked alongside network adaptors as part of a comprehensive spares strategy. These modules share the same Momentum I/O base form factor and are installed without tools, making them straightforward to include in a single procurement order.

Where the migration scope extends to the host controller level, facilities transitioning from a Modicon Quantum 140CPU65150 or 140CPU67160 to a modern Modicon M340 or Modicon M580 platform will need to address the Modbus Plus to Ethernet/IP or Modbus TCP protocol bridge. The 174CEV30010 Ethernet communication module or a dedicated protocol gateway is typically introduced at this stage to preserve the existing Momentum I/O investment while the host controller is upgraded.

Power integrity is a frequent concern during Momentum I/O island audits. The 170PNT11000 power supply module, which provides 24 VDC to the Momentum I/O base assembly, should be inspected and load-tested whenever a network adaptor replacement is being performed — capacitor aging in the PSU can cause marginal voltage conditions that accelerate adaptor failures. Replacing both the 172PNN26022 and the power supply module in a single maintenance window is a common best practice.

For facilities that retain Modbus Plus as the field network but need to integrate newer HMI panels, the Magelis XBTGT series HMI with Modbus Plus communication option provides a modern operator interface without requiring a protocol migration. This approach is particularly cost-effective in applications where the PLC program is stable and the primary driver for modernization is an aging or discontinued HMI panel rather than the control logic itself.

Finally, where signal isolation between the Modbus Plus segment and field instrumentation is required — particularly in environments with high electrical noise from variable frequency drives or large motor starters — signal isolators and surge protection modules compatible with the Momentum terminal base wiring are recommended as part of the retrofit bill of materials.

Retrofit Guidance FAQ

Q: Can I replace the 172PNN26022 without modifying the PLC program?
Yes. The 172PNN26022 is a like-for-like replacement. The Modbus Plus node address is set via rotary switches on the adaptor face. As long as the replacement unit is configured to the same node address as the failed module, the host Modicon Quantum or Premium PLC will resume communication with the I/O island without any program changes.

Q: Is rewiring required when installing the replacement adaptor?
No field wiring changes are required. The 172PNN26022 connects to the Modbus Plus trunk via a standard DB9 connector. The I/O base terminal blocks remain undisturbed. The adaptor plugs directly into the I/O base — the only physical action required is removing the failed unit and inserting the replacement.

Q: What if my Modbus Plus network shows communication errors after installing the replacement?
First verify the node address rotary switch settings match the original configuration. Then check the Modbus Plus cable termination resistors at both ends of the trunk segment — a missing or damaged 150-ohm terminator is a common cause of post-replacement communication faults. Use a Modbus Plus diagnostic tool (SA85 or equivalent) to verify network token rotation before returning the system to production.

Q: Can the 172PNN26022 be used with a Modicon M340 or M580 host controller?
The M340 and M580 platforms use Modbus TCP over Ethernet as their primary network. Direct Modbus Plus connectivity requires a protocol gateway or a BMX NOM 0200 Modbus Plus communication module (M340 specific). The 172PNN26022 itself remains fully functional on the I/O side — the integration point is at the host controller communication architecture.

Q: What is the physical installation space requirement?
The 172PNN26022 adaptor mounts directly to the Momentum I/O base with no additional DIN rail space or panel cutout required. The overall footprint of the I/O island is unchanged. This makes it suitable for retrofit in existing control cabinets where space is constrained.

Q: How do I confirm the module is genuine and functional before installation?
All units supplied by TOPNLMS undergo pre-shipment functional testing. Each module is inspected for physical integrity, firmware version, and communication response. A test report is available on request. The 12-month warranty covers any latent defects identified after installation.

Warranty Assurance

Every Schneider Electric 172PNN26022 supplied by TOPNLMS is backed by a 12-month warranty from the date of shipment. Our warranty commitment covers:

• Pre-shipment functional testing: Each unit is powered and tested for Modbus Plus communication response before dispatch. Modules that do not pass testing are not shipped.
• Replacement support: In the event of a warranty claim, TOPNLMS will dispatch a replacement unit promptly to minimize your system downtime. Return freight for confirmed warranty failures is covered.
• After-sales response: Our technical team is reachable by email and phone for installation guidance, configuration questions, and fault diagnosis support throughout the warranty period.
• Procurement assurance: We maintain stock of Momentum series components specifically to support emergency replacement and planned maintenance procurement. Lead times and stock levels are confirmed at the time of order.
• Documentation: Datasheet, wiring diagram references, and firmware version information are provided with each shipment on request.

For volume procurement, scheduled maintenance contracts, or multi-site spares programs, contact our team directly to discuss pricing, lead time guarantees, and consignment stock arrangements.