The D22HC Half Duplex Multimode Latching dual 2x2 optical switch is two half duplex 2x2 optical switches in one switch with an extra path in state 2.  If looking at it as 2 single half duplex 2x2s, fibers 1, 2, 7 and 8 make up one 2x2 while fibers 3, 4, 5 and 6 make up the other. Note the extra path connecting fibers 2 and 6.
 
Although most applications do not require the connection between fibers 2 and 6 in state 2, it is often not an issue and in some cases may be a desired feature (e.g. a loopback for self-testing of a transmitter/receiver pair).
 
The latching version of the D22HC Half Duplex Multimode switch requires no steady state input power. The switch is set to state 1 or state 2 by a single pulse of 20 milliseconds or longer. Continuous current is preferable to maintain the switched state under high vibrational stress. The latching design retains its switched state during a power loss.
 
Cables and Cable Length
   All cables are 900µm tight buffer and 1.0 meter length.  Custom lengths are available at additional cost.
 
Voltage
   Standard input voltage 5 Volts and a 50 ohm coil.  Other options are available on request.