Fire optic plug for V.24 data transfer with DTE or DCE configuration (IBM PC compatible). Connections for PMMA tape conduit 1000 μm (UN1 adapter), PMMA sheathed cable 1000 μm (UN2 adapter) and fibreglass 50 / 125 μm or 62.5 / 125 μm (ST) are available.
The optical signal layer is not inverting (idle state: light off)