The 44474A Digital I/O offers 16 very flexible bidirectional I/O lines and 4 TTL-compatible handshake lines for sensing and control of external devices. The digital inputs can be used to sense contact closures to ground. Each channel provides current sinks for remote switching of external relays, such as the 33311 series coaxial switches. This unit is Option 014 plug-in module for the 3488A Switch/Control Unit.
