Moxa TCF-90-S-ST , Power RS232 to Single-mode ST fiber optic cable content_copy

The TCF-90-S-ST from Moxa is a compact RS-232-to-fiber optic converter designed for lossless transmission of serial data over fiber optic cables. The device enables conversion of RS-232 signals into optical signals, which can be transmitted over singlemode fibers up to a distance of 40 km. Optical isolation protects data from ground potential differences, electromagnetic interference (EMI), and chemical corrosion, making it particularly suitable for industrial environments and safety-critical applications. Power supply is either via the serial interface (through signal lines TxD, RTS, DTR) or optionally via an external DC power supply or USB. The optical connection is made via an ST connector, ensuring a secure and stable connection.

Applications
This converter is designed for industrial control systems, building automation, and secure data connections between buildings. It is especially suitable where galvanic isolation of data lines is required to avoid disturbances caused by ground loops or voltage differences. The high transmission range of up to 40 km with singlemode fibers also makes it suitable for applications over long distances, such as in power supply or public transportation.

Functions and Features in Detail
The TCF-90-S-ST features an automatic LED port power indicator, visually signaling the operational status of the port. The serial interface is implemented via a DB9 female connector, enabling standard connectivity for many industrial devices. An integrated test mode, activated via switch SW4, allows testing of the power supply and supports troubleshooting during installation. It is recommended to set RTS or DTR to ON to ensure reliable power supply via the serial interface. When handshake lines are inactive, an external power supply is recommended.

Technology Explained Simply
The conversion of RS-232 signals into optical signals is performed by an integrated transceiver, which converts electrical signals into light pulses and transmits them over the fiber optic cable. The reverse conversion occurs at the receiver end. Optical isolation ensures no electrical connection exists between devices, preventing disturbances caused by ground voltages or electromagnetic interference (EMI/RFI). The use of singlemode fibers enables high bandwidth and long transmission distances, as light is guided in a single mode, minimizing distortion.

Compatibility and Accessories
The converter is designed for use with singlemode fiber optic cables. Connection is made via an ST connector, which is standard in many industrial and telecommunication applications. Power supply via the serial interface requires that signal lines TxD, RTS, and DTR are active to provide the supply voltage. For devices that do not use these lines, an external power supply is required.

Installation and Mounting
Installation is performed via the DB9 female connector on the serial interface of the connected device and the ST connector on the fiber optic cable. Wiring is simple and does not require special tools. The LED indicator supports visual verification of operational status. The recommendation to use RTS or DTR for power supply should be considered during configuration to ensure reliable operation.

Operational Advantages
Galvanic isolation via optical isolation increases operational safety and reduces interference. The long transmission range of up to 40 km with singlemode fibers enables flexible network designs. The option to power the device via the serial interface or externally offers flexibility during installation. The compact design and simple operation via the LED indicator and test mode facilitate integration into existing systems.