ATEN IC485SN RS-232 to RS-485/RS-422 Serial Interface Converter

Overview

The ATEN IC485SN is a rack-mountable serial interface converter that bridges RS-232 equipment to RS-485 or RS-422 serial networks — a common requirement when integrating legacy access control panels, PTZ camera controllers, or building automation devices that speak RS-232 into longer-run serial bus topologies. The IC485SN extends usable signal distance up to 1200 m (4000 ft) at data rates up to 100 Kbps, making it practical for cross-building or campus-scale wiring runs where RS-232's native ~15 m limit falls far short. With selectable DCE/DTE mode and multiple TX/RX trigger options (TxON/RxON, TxRTS, TxDTR/RTS, RxDSR/ON), the converter adapts to a range of handshaking schemes without rewiring.

Compatibility

Connects any RS-232 host — including serial PTZ controllers, legacy DVRs with RS-232 control ports, CCTV matrix switchers, access control panels (Lenel, Software House, Honeywell Pro-Watch, and similar systems with RS-232 serial ports), and industrial PLCs — to RS-485 or RS-422 two-wire or four-wire bus runs. The DB-25 Female RS-232 interface mates with standard DB-25 serial ports or DB-25-to-DB-9 adapters. The RS-485/RS-422 side terminates to a four-terminal block for direct wire connection. The RJ-11 female port supports daisy-chain or loop configurations typical in multi-drop RS-485 deployments. Operates in environments up to 80% RH non-condensing.

Installation Notes

Set the DCE/DTE switch to match the RS-232 host's port type — incorrect mode selection is the most common cause of no-communication on first install. Select the TX enable method (TxON, TxRTS, or TxDTR/RTS) to match the host device's handshaking behavior; RS-485 half-duplex buses require the converter to manage bus direction automatically or via RTS. Wire the RS-485/RS-422 terminal block with attention to polarity (A/B differential pair) — reversed polarity causes data corruption, not silence, which can be harder to diagnose. Maximum data rate of 100 Kbps is achievable at full 1200 m only with properly terminated cable; unterminated long runs will reduce reliable throughput. Rack-mount form factor fits standard 19-inch enclosures.