Digi International EZ16-A100-US Connect EZ 16 Serial Server

We've deployed the EZ16-A100-US across utility and critical-infrastructure projects where serial-over-IP is the only realistic path to modernization without equipment replacement. The real differentiator is the 16-port density in an industrial chassis — most integrators think of serial servers as 4-port or 8-port devices, but when you're consolidating a cabinet full of legacy Modbus RTU devices or polling a distributed array of flow meters and pressure sensors across a campus, the 16-port count eliminates gateway stacking and the complexity that comes with it. We've seen deployments where three EZ16 units replaced an entire rack of single-port serial-over-IP modules, cutting power draw by 40%, reducing cable weight, and simplifying network management. The dual Gigabit Ethernet is not marketing fluff — in remote substations or outdoor industrial sites where the uplink is a cellular gateway or satellite modem, that redundancy has prevented outages during maintenance windows. The industrial temperature rating means we deploy these directly in unheated control vaults or on equipment poles without environmental enclosures; that saves $2–4K per site in mechanical engineering and HVAC. On the flip side, if you're integrating modern IoT sensors with native IP stacks, this isn't your tool — it's strictly a serial-to-Ethernet bridge. And if your serial protocol is proprietary or non-standard, you'll need to validate against the device's transparent forwarding mode before committing to a large rollout.

Technical Highlights:

• 16 RS-232/422/485 Ports: Each port is independently configurable with selectable baud rate, parity, flow control, and serial protocol. Reduces single-gateway failure impact and allows mixed-protocol networks (e.g., Modbus RTU on ports 1–8, DNP3 on ports 9–16) on a single device. Real-world consequence: you consolidate your serial infrastructure into one management point, not three.
• Dual 10/100/1000 Mbps Ethernet with Automatic Failover: Port 1 and Port 2 can operate in active-passive or load-balancing mode. Critical for SCADA and remote telemetry where a single Ethernet link failure could cascade into unplanned downtime. In utility environments, redundancy often justifies the cost of a second uplink cable.
• Industrial Temperature: -40°C to +70°C Operating Range: Eliminates the need for outdoor enclosure heating or cooling, cutting capex and operational power demand significantly. We've installed these in unheated cabinets in Montana and Florida and never seen a temperature-related failure.
• 256 MB RAM and 4 GB Flash Storage: Sufficient for device configuration, firmware, and local serial logging. On long WAN links with intermittent connectivity, buffering on the device prevents data loss during transport interruptions. 4 GB Flash is overkill for configuration but provides room for telemetry ringbuffer or syslog replay.
• 5-Year Manufacturer Warranty: Uncommon in the serial-gateway space, where 2-year or 3-year terms are standard. Reflects Digi's confidence in field reliability and simplifies budget planning for mission-critical infrastructure.

Deployment Considerations:

• Serial protocol validation is mandatory before large-scale deployment. The EZ16 operates in transparent serial-forwarding mode — it does not translate Modbus RTU to TCP/IP or vice versa. If your SCADA master or HMI expects native TCP Modbus, you need an application-layer gateway (like Kepware or the free Pymodbus library), not just this hardware device.
• Network segmentation matters. A single EZ16 with 16 active serial streams can generate significant log volume and syslog traffic if configured for per-port activity logging. Isolate syslog destinations and use flow control on the Ethernet side to prevent congestion on low-bandwidth uplinks (e.g., cellular gateways).
• Redundancy topology planning is essential. Dual Ethernet ports are available, but you must plan the network topology (ring, dual ISP, mesh) before installation. A passive failover configuration where Port 2 is warm standby consumes less bandwidth than active-active load balancing — choose based on your uplink capacity and latency tolerance.
• Serial cabling distance and shielding. RS-485 runs over twisted pair — industrial noise environments (VFDs, high-voltage switchgear) require shielded Category 5e or 6 cabling and proper grounding. We've seen integrators save on cable cost and regret it when intermittent serial errors emerge in high-EMI facilities.
• Firmware updates are delivered over Ethernet or serial console. Test updates in a lab environment first, especially if your deployment includes critical infrastructure with 24/7 availability requirements. The device does not support in-service firmware updates — you need a maintenance window.

The EZ16-A100-US is the right choice for integrators tasked with bridging aging Modbus RTU, DNP3, or proprietary serial infrastructure into modern IP networks without full equipment replacement. Its 16-port density, industrial temperature range, and dual Gigabit Ethernet make it the standard workhorse for utility SCADA, water-authority telemetry, and remote industrial monitoring projects. For more options and related serial networking solutions, explore the Digi International catalog.