Description
Note: Many products are not yet listed. Please contact us for more product information. Our supply channels are constantly expanding, and we currently have 20 stable shared supply channels. Please confirm the model, product, price, and all other necessary information with customer service before placing an order. We offer new, refurbished, and used products, and prices are adjusted according to the year of the item you require.
Product Introduction
When a refinery’s control network drops 3 consecutive PLC communication sessions mid-run, the root cause almost always traces back to an unmanaged industrial switch that can’t handle EMI noise from adjacent VFDs.
This A4 Series switch is purpose-built for harsh industrial network deployments. It natively supports 24 copper RJ45 ports plus 4 flexible SFP fiber uplinks, eliminating the need for external media converters for long-distance fiber runs. Its 17.6Gbps non-blocking switching fabric ensures zero packet drops even under 100% full load traffic conditions.
A4H124-4FX P0973JN
A4H124-4FX P0973JN
A4H124-4FX P0973JN
A4H124-4FX P0973JN
Key Technical Specifications
| Parameter | Value |
|---|---|
| Downlink Ports | 24 × 10/100Base-TX RJ45 (auto MDI/MDI-X) |
| Uplink Ports | 4 × 100Base-FX / 1000Base-X SFP slots |
| Switching Capacity | 17.6 Gbps |
| Forwarding Rate | 9.5 Mpps |
| MAC Address Table | 16K entries |
| Max Supported VLANs | 4096 (IEEE 802.1Q) |
| Link Aggregation | LACP 802.3ad, up to 8 groups |
| Spanning Tree | STP / RSTP / MSTP |
| Stacking | Up to 8 switches per stack |
| Management | CLI, Web UI, SNMP v1/v2/v3, Telnet |
| Security | 802.1X, port security, MAC filtering, ACL |
| Operating Temperature Range | 0°C to +50°C |
| Power Supply | 100–240VAC universal input |
Field Application & Technical Pitfalls
This part runs three non-negotiable production-critical roles.
First, it serves as the core access switch for refinery DCS control networks, where zero packet loss is mandatory for PLC-to-HMI communication.
Second, it delivers long-distance fiber uplinks for campus building network backbones, connecting 24 end-user devices to the core network over multi-mode fiber runs up to 2km.
Third, it acts as the redundant edge switch for power plant SCADA networks, supporting rapid RSTP failover in under 300ms.
⚠️ SFP Port Speed Lock Risk: The 4 SFP ports default to auto-negotiation on power-up. If you plug in a 100Mbps SFP module without manually locking the port speed, you’ll get 40%+ packet loss that breaks all long-distance fiber links.
⚠️ Stacking Cable Misalignment: The rear stacking ports are not hot-swappable. If you pull the stacking cable while the stack is powered on, you’ll split the stack into two independent broadcast domains and trigger a full network storm.
⚠️ 802.1X Authentication Bypass: If you forget to add the PLC MAC addresses to the port security whitelist, the switch will lock the control ports after 5 minutes of failed authentication, taking all connected I/O devices offline.
I watched a junior network tech skip the port whitelisting step last quarter. He swapped this switch into a water treatment plant SCADA network, enabled 802.1X by default, and the switch locked all 24 control ports 10 minutes later. The entire plant’s PLC network went dark, and the operations team spent 3 hours troubleshooting before they found the port security lockout. That 2-minute configuration oversight forced the plant to run all manual control loops for the rest of the shift.
Quality Control (QC) SOP & Transparency
- Inbound Verification: Cross-check the OEM serial number against Enterasys’s official part revision database, run anti-counterfeit validation on the module’s laser-etched serial label, and confirm no prior rework traces on the RJ45 port solder joints.
- Live Rig Testing: Power up the switch, connect 24 test devices plus 4 SFP fiber links, and verify full 17.6Gbps non-blocking throughput across 4 hours of 100% load testing.
- Parameter Testing: Perform 1500V AC 60-second dielectric withstand test across all signal ports and chassis ground, confirm zero packet loss at full throughput, and log all latency data for every port.
- Final QA & Packaging: Seal the fully tested switch in a static-shielding anti-static bag, apply a unique QC passed serial label, and pack it in ESD-dissipative foam with a printed hard copy of the full throughput test report.
Frequently Asked Questions
- Can I hot-swap SFP modules while the switch is powered on? Yes, the SFP ports support hot-plug. But you must disable the port first in the CLI before swapping — the switch will log a critical fault alarm if you pull the module while the port is active.
- What exact Enterasys firmware versions does this part work with? It is fully compatible with all A4 Series firmware v6.5 or newer. It will not establish stable stacking connections with older v6.2 firmware released before 2010.
- How long is the standard warranty for this new surplus unit? It carries a full 12-month functional warranty. If it fails within that window under specified operating conditions, we cover all return shipping and bench replacement costs.
- How do I tell a genuine OEM unit apart from a refurbished clone? Genuine units have the Enterasys hologram sticker on the rear of the housing, and the RJ45 ports use gold-plated 8-pin connectors. Refurbished clones usually skip the hologram and use tin-plated RJ45 pins that corrode in high-humidity industrial environments.
- Will this A4H124-4FX directly replace an older A2H124-24FX switch? No. The A2 series only supports 8.8Gbps switching capacity, while this A4 unit doubles that to 17.6Gbps. You will need to reconfigure the stacking parameters after swapping to match the new higher throughput limits.
- What’s the maximum safe continuous operating temperature at full 100% load? It will hold zero packet loss up to 50°C, though your mileage may vary if the rack cooling airflow drops below 20 CFM and internal component temperatures spike 15°C above ambient.
