The ATC ATC-277MM-XX modem manual describes its RS-232/RS-422/RS-485 interfaces, fiber connections, specifications and installation.
The ATC-277MM-XX is a multifunction fiber optic modem that supports RS-232, RS-422 and RS-485 asynchronous communication interfaces. It is designed for linking remote terminal units (RTU) to hosts or SCADA controllers and can operate in full‑duplex or half‑duplex modes.
The manual provides wiring details for the RS‑232 DB‑9 connector, RS‑422/RS‑485 terminal block, fiber optic connectors (SC, ST, FC) and lists the key technical specifications such as data rates, power requirements, operating temperature and certifications. This manual is written in Chinese.
| Transmission medium | Dual‑core multimode fiber |
|---|---|
| Fiber transmission distance | 2 km |
| Fiber wavelength | 850 nm |
| Fiber interface types | SC, ST, FC |
| Data interfaces | RS-232, RS-422, RS-485 |
| Transmission mode | Asynchronous full‑duplex, half‑duplex |
| RS-232 data rate | 0‑115.2 KBPS |
| RS-422/RS-485 data rate | 0‑920.6 KBPS |
| RS-485/RS-422 transmission distance | 0‑1.2 km |
| Power supply | 9‑24 V DC @ 250 mA max |
| Operating temperature | -40 °C to 70 °C |
| Certifications | CE, FCC Class A |
| Dimensions (L×W×H) | 96 mm × 66 mm × 26 mm |
| Weight | 0.40 kg |
The modem can transmit over dual‑core multimode fiber up to 2 km.
It supports RS‑232, RS‑422 and RS‑485 asynchronous serial interfaces.
The device operates from a 9 V to 24 V DC supply, drawing up to 250 mA.