INTRODUCTION The Model 7158 Low Current Scanner Card has ten channels of paired single-pole single-throw (SPST), normally open (NO) relays. The card will switch any one of ten signals to one output, or switch one signal to any one of ten outputs. Signal HI is connected to signal LO (analog ground) when the scanner mainframe channel is open, and to output HI when the channel is closed. Signal LO is common to all ten channels and the output. An additional relay isolates all circuitry on the card from the output when no channel is closed. Features of the scanner card include: • Low offset current error (<1pA specified, <30fA typical). • Switching of AC or DC signals up to 100mA. • BNC input and output connectors. • Two outputs for daisy-chaining of Model 7158 cards. • Configurable for low current or low voltage switching. The Model 7158 is field-installable in the Models 705 and 706 scanner mainframes.