General
Number of serial ports	2
Wavelength Single-Mode	1310 nm
Maximum range single-mode	40 km
Link budget multi-mode	15 dB
Link budget single-mode	20 dB
Dispersion penalty	1 dB
MTBF	2.272.562 Stunden
Safety standard	UL 60950-1

The Moxa TCF-90-M-ST is a compact RS-232 to fiber optic converter, enabling the conversion of serial signals into optical signals for transmission over fiber optic cables. Power supply is provided via the RS-232 port, allowing the converter to operate without an external power source in many cases. Alternatively, it can be powered via a USB power cable or a DC power supply.

Applications
This converter is suitable for industrial and building applications where serial communication over fiber optic is required. The use of fiber optic eliminates electromagnetic interference, ground potential differences, and other noise sources, enhancing signal quality and transmission reliability. The maximum transmission distance is 5 km with multi-mode fiber (850 nm) and 40 km with single-mode fiber (1310 nm), making it suitable for medium to long distances. Its compact design and desktop mounting make it ideal for installations with limited space.

Functions and Features in Detail
The TCF-90-M-ST features two serial RS-232 ports with DB9 female connectors. Supported baud rates range from 300 bps to 115.2 kbps, with active signal pins TxD, RxD, and GND. Control pins DTR, DSR, DCD, CTS, and RTS are internally bridged, enabling easy integration into existing systems. An LED indicator shows whether the converter receives sufficient power through the serial interface, simplifying troubleshooting of operational issues.

Technology Explained Simply
The optical interface supports multi-mode fiber at a wavelength of 850 nm and single-mode fiber at 1310 nm. TX power ranges from 0 to -5 dBm, while RX sensitivity is 0 to -20 dBm (multi-mode) and 0 to -25 dBm (single-mode). The link budget is 15 dB (multi-mode) and 20 dB (single-mode), with a dispersion penalty of 1 dB taken into account. These values ensure stable and reliable data transmission over the specified distances.

Compatibility and Accessories
The converter is compatible with standard RS-232 devices and can be integrated into existing serial networks. Powering via the RS-232 port requires the connected device to supply sufficient power. Included as an accessory is a USB power cable (50 cm), serving as an alternative to serial power supply. The use of an external DC power supply is also possible.

Mounting and Installation
The converter is delivered in desktop configuration and can be placed directly on a surface. Its compact dimensions of 42 x 80 x 22 mm and weight of 150 g allow for flexible placement. Mounting requires no special tools or additional brackets. Installation is performed by connecting serial devices to the DB9 connectors and attaching the fiber optic cable to the ST connector.

Operational Advantages
The use of fiber optic provides high immunity to electromagnetic interference and enables secure data transmission over long distances. Powering via the RS-232 port reduces the number of required cables and minimizes installation effort. The integrated overcurrent protection function safeguards the converter against damage from excessive current draw. Certifications according to EN 55032/35, CISPR 32, FCC Part 15B, and IEC 61000-4-x series, as well as safety standard UL 60950-1, ensure reliable and safe operation. The MTBF is 2,272,562 hours according to Telcordia standard, indicating high longevity. The operating temperature range of 0 to 60°C and storage temperature range of -20 to 75°C allow use in a wide range of environments. Humidity levels from 5 to 95% (non-condensing) are also suitable for various climatic conditions. The protection rating IP30 protects against contact with moving parts and larger solid objects, but not against water or dust.

Scope of Delivery
The scope of delivery includes the TCF-90 converter, a USB power cable (50 cm), a quick start guide, and a warranty card. The warranty period is 5 years; further details are available on the manufacturer’s website.