Is Your Legacy Modbus Plus Network Holding You Back?
Many plants still run critical processes on Modbus Plus networks. When a communication adapter fails, production stops and replacement options shrink every year. The Schneider 172PNN21022 keeps those networks alive. This Modbus Plus option adaptor belongs to the Modicon Momentum automation platform. It plugs into an I/O base and adds one Modbus Plus communication port to your existing Momentum assembly.
What Makes This Adapter a Smart Replacement Choice
Instead of ripping out a working control system, you can restore communication with one compact module. The 172PNN21022 measures just 25 mm high, 143.1 mm wide, and 60.06 mm deep. It weighs only 85.05 g, so it fits into tight cabinets without mechanical redesign. The module draws its 5 V DC supply directly from the I/O base, which means no separate power wiring. A single LED shows communication status at a glance, so technicians can confirm network activity in seconds.
Key Specifications at a Glance
| Parameter | Value |
|---|---|
| Product type | Modbus Plus option adaptor |
| Platform | Modicon Momentum |
| Communication port | 1 x Modbus Plus, single type |
| Electrical connection | 9-pin D-shell connector |
| Rated supply voltage | 5 V DC, +/- 5 % tolerance |
| Supply source | Via I/O base |
| Current consumption | <= 350 mA at 24 V DC (200 mA typical) |
| Battery | Lithium, 2/3 AA, 5-year life |
| Battery backup | < 30 days after low indication at 40 °C |
| Clock drift | +/- 13 s/day |
| Local signalling | 1 communication LED |
| Dimensions (H x W x D) | 25 x 143.1 x 60.06 mm |
| Net weight | 85.05 g |
| IP degree of protection | IP20 per IEC 529 |
| Operating temperature | 0…60 °C |
| Storage temperature | -40…85 °C |
Why the Battery and Clock Accuracy Matter
Two specs often decide whether this module suits your application. First, the lithium 2/3 AA battery lasts about five years. After the low-battery indication appears, you still have under 30 days of autonomy at 40 °C to schedule a replacement. Second, clock drift stays within +/- 13 s/day. For timestamping and event sequencing on a Modbus Plus segment, that accuracy keeps logs consistent between nodes.
Where the 172PNN21022 Fits Best
Legacy line upgrades. A food plant running a Momentum I/O base can add Modbus Plus connectivity without replacing the whole rack. The adapter snaps into the platform and uses the existing 5 V DC backplane supply.
Spare parts strategy. Maintenance teams that stock one adapter avoid multi-day downtime when a network port fails. The 85.05 g module stores easily and survives -40…85 °C storage conditions.
Controlled-cabinet installations. With IP20 protection and a conformal coating (TC treatment), the module suits clean panels, not washdown floors. Keep it inside an enclosure where humidity stays between 5 % and 95 % without condensation.
Installation and Setup Guidance
Mount the adaptor on the Momentum I/O base and secure the 9-pin D-shell connector for the Modbus Plus link. Verify the 5 V DC supply comes from the base before power-up. Watch the communication LED during startup; steady or blinking activity confirms the port is alive. Keep the cabinet within 0…60 °C and below 2,000 m altitude. Route network cable away from drives and high-current conductors to reduce electromagnetic interference, since the module is tested to 10 V/m across 80…1000 MHz.
Reliability and Maintenance Planning
Inspect the D-shell connection periodically for bent pins or loose retention. Log the battery installation date and replace the lithium cell before the five-year mark; the low-battery window is short at elevated temperatures. The module resists 15 gn shock and 1 gn vibration from 57…150 Hz, so normal panel vibration is not a concern. For safety-related inspections, follow your plant’s standard procedures and the manufacturer’s documentation.
Compatibility and Integration Notes
The 172PNN21022 works inside the Modicon Momentum automation platform and speaks Modbus Plus natively. It carries CE marking, UL, CSA, and NEMA 250 type 1 certifications, and follows IEC 529 for ingress protection. Confirm your controller and network segment support Modbus Plus before ordering, because this adapter serves that protocol only.
What to Verify Before You Buy
Check three things: your I/O base provides the 5 V DC supply, your network uses Modbus Plus, and your cabinet meets the IP20 environment limits. If you need the matching connector or battery, ask the team at SpareTechPLC to confirm what ships with each unit. Please verify current lifecycle status and availability with SpareTechPLC before ordering, since legacy platform stock changes quickly.
Frequently Asked Questions
Does the 172PNN21022 need external power? No. It receives 5 V DC through the I/O base, with +/- 5 % input tolerance.
How long does the lithium battery last? About five years. After the low indication at 40 °C, you have under 30 days of backup.
What connector does the Modbus Plus port use? One 9-pin D-shell connector, single port type.
Can I use it outside a cabinet? No. IP20 protection limits it to controlled environments between 0…60 °C.
Which platform does it belong to? The Modicon Momentum automation platform, as a Modbus Plus option adaptor.
