The D22HC half duplex 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 standard non-latching version of the D22HC Half Duplex Singlemode switch requires continuous drive current and functions like a conventional relay, which may not retain state during a power loss (Power off = State 1).  Choose the Reverse non-latching option to change to the bypass state during a power loss (Power off = State 2).
 
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.