General
Wavelength	1300 nm
Dispersion penalty	3 dB
Air humidity	5–95 % (nicht kondensierend)

The IMC-21A-M-SC from Moxa is an industrial media converter that enables conversion of 10/100BaseT(X) Ethernet connections via RJ45 interface into 100BaseFX fiber optic connections. It is specifically designed for use in demanding industrial environments where high reliability, temperature resistance, and mechanical robustness are required. The device features a metal housing that protects against mechanical stress and environmental influences, and is designed for mounting on a DIN rail, enabling flexible integration into existing enclosures.

Applications
This converter is ideal for industrial automation environments such as factory networks, power supply systems, or transportation technology, where connecting Ethernet networks over long distances using fiber optics is necessary. The fiber optic connection offers higher immunity to interference, greater transmission distances, and resistance to electromagnetic disturbances compared to copper cables. The model designation IMC-21A-M-SC refers to a multi-mode fiber with SC connector, suitable for transmission distances up to 4 km.

Functions and Features in Detail
The converter includes an RJ45 interface for Ethernet connection and an SC connector for fiber optic. Configuration is performed via DIP switches, allowing settings for duplex mode, transmission speed, and operating mode. An integrated Link Fault Pass-Through (LFPT) feature ensures that if the fiber optic connection fails, the Ethernet link is also interrupted, simplifying network monitoring. Power supply is via a terminal block with voltage ranging from 12 to 48 VDC, including overcurrent and reverse polarity protection to prevent damage from incorrect operation.

Technology Explained Simply
The wavelength of the optical transmission is 1300 nm for multi-mode fibers, enabling efficient data transmission over medium distances. The TX power ranges from -10 to -20 dBm, indicating the signal strength at the transmitter, while the RX sensitivity ranges from -3 to -32 dBm, indicating the receiver’s ability to detect weak signals. The link budget of 12 dB for multi-mode fibers specifies the maximum attenuation the system can tolerate without breaking the connection. The dispersion penalty of 3 dB accounts for signal distortion due to modal dispersion in multi-mode fibers.

Compatibility and Accessories
The IMC-21A-M-SC is compatible with standard 10/100BaseT(X) Ethernet networks and can be combined with other models from the IMC-21A series to establish fiber optic connections between different devices. The series is available in various variants, including models with ST connectors or single-mode fiber, each designed for different applications and transmission distances.

Mounting and Installation
Mounting is done via a DIN rail, enabling quick and secure installation in enclosures. The protection rating IP30 ensures protection against solid foreign objects and splashing water, but not against dust or prolonged water exposure. The operating temperature is -10 to 60 °C for the standard model, while the -T versions can operate from -40 to 75 °C, enabling use in extreme environments. The relative humidity must be between 5 and 95 %, provided no condensation occurs.

Operational Advantages
The converter offers high stability and reliability thanks to its robust metal housing and integrated protection functions. The extended operating temperature allows use in climatically demanding environments, such as outdoor installations or cooling systems. The simple configuration via DIP switches reduces installation time and minimizes error sources. The 5-year manufacturer’s warranty underscores the product’s quality and durability.

Scope of Delivery
The scope of delivery includes the IMC-21A-M-SC media converter, a quick start guide, and a warranty card.