Description
Application Scenarios
In a refinery FCC unit DCS retrofit, engineers faced a typical challenge: field FBM cabinets were distributed across multiple process areas, with the farthest distance exceeding 400 meters, and located near high-power motors and variable frequency drives. Traditional Cat5 copper links frequently experienced CRC errors and intermittent communication dropouts, causing controllers to report “communication timeout” faults, leaving operators unable to reliably monitor reaction temperatures.
After replacing the links between field cabinets and the central control room with Foxboro A2H124-24FX P0973BJ switches, 24 × 100Base-FX multimode fiber ports directly connected the Foxboro controllers in each remote I/O cabinet, with MT-RJ interfaces providing compact high-density cabling. Fiber transmission completely eliminated ground loops, and electromagnetic pulses from motor start/stop no longer coupled into communication lines. After the retrofit, network-related faults in that process area dropped from an average of 3 per month to zero, significantly improving DCS availability.
In power plant boiler DCS control cabinet edge aggregation scenarios, the A2H124-24FX P0973BJ similarly handles the aggregation task for dozens of field controller fiber downlinks. Its factory-preloaded DCS QoS policies mark Modbus TCP and Foxboro proprietary control messages as highest priority, ensuring control commands are still forwarded preferentially during data congestion .
Parameters
| Parameter | Value/Description |
|---|---|
| Product Model | A2H124-24FX P0973BJ |
| Manufacturer | Enterasys Networks (now Extreme Networks) / Foxboro OEM |
| Product Category | Managed Fiber Ethernet Switch (Layer 2 Stackable) |
| Fiber Ports | 24 × 100Base-FX Multimode Fiber (MT-RJ interface, 1310 nm) |
| Uplink/Stacking Ports | 2 × SFP Mini-GBIC Gigabit Slots + 2 × 10/100/1000Base-T RJ45 |
| Switching Capacity | 12.8 Gbps (standalone) / 102.4 Gbps (stacked) |
| Forwarding Rate | 9.5 Mpps (standalone) / 76.2 Mpps (stacked) |
| MAC Address Table | 8,000 entries |
| VLAN Support | IEEE 802.1Q, up to 4,096 VLAN IDs |
| Management | CLI (Console/SSH/Telnet), Web GUI, SNMP v1/v2/v3, RMON |
| Stacking Capability | Up to 8 SecureStack A2 series switches in a unified stack |
| Power Input | 100–240 VAC, 50/60 Hz; optional redundant power supply (RPS) supported |
| Power Consumption | Maximum 59 W (full load) |
| Operating Temperature | 0°C to +50°C (standard commercial grade) |
| Storage Temperature | -40°C to +70°C |
| Dimensions (W×H×D) | 44.1 × 4.4 × 21.0 cm (standard 19-inch 1U rack) |
| Mounting | 19-inch rack mount (1U) |
