The 7709 plug-in module is a two-pole, 68 matrix module. It can connect any combination of six differential channels of instrumentation to any combination of eight differential device under- test channels. The instrumentation can be AC and DC sources, internal or external meters, oscilloscopes, etc. This matrix configuration allows wide flexibility for complex test systems. Expandable to larger switch configurations by daisychaining or cascading multiple modules Two female D-sub connectors are standard for secure hook-up and quick tear-down Relay closures stored in on-board memory Automatic two or four-wire connection to DMM 300V, 1A Capacity &lt, 1W Contact resistance at any path and additional 1W at end of contact life &lt, 3µV Per contact pair, contact potential &lt, 100pA Offset current