The X22 is a bidirectional TTL to the fiber-optic converter in a small form factor. It lets the user convert to and from fiber-optic signals to and from digital voltage signals. The unit is independently powered from an isolated power supply, allowing for high voltage isolation between TTL input and outputs when two X22s are used as a pair.
The polarity of conversion is configurable with two physical switches one for each direction. TTL inputs can be high impedance or 50 ohm, settable with an internal jumper specified when you order. The fiber optic connectors can be either ST type or Versatile Link style specified when you order. The X22 is built with robust components for reliable performance under many operating conditions.
The X22 can be used to convert UART communication signals, like RS232, to and from fiber optics using standard baud rates.
For unidirectional TTL to fiber applications that can drive 30mA the TF-1 may be a simpler choice.
If you wish to "fan-out" the signal to multiple fiber outputs, see the X14 device.