Chapter 3 Theory of Operation© National Instruments Corporation 3-3 SCXI-1163 User ManualSCXIbus Connector Signal DescriptionsPin Signal Name DescriptionA19 RESET* Reset – When pulled low, reinitializes the module to itspower-up state. Totem pole. Input.B19 MISO Master-In-Slave-Out – Transmits data from the moduleto the SCXIbus. Open collector. I/O.C19 D*/A Data/Address – Indicates to the module whether addressinformation or data information is being sent to themodule on MOSI. Open collector. I/O.D19 INTR* Interrupt – Active low. Causes data that is on MOSI tobe written to the Slot 0 Slot-Select Register. Opencollector. Output.A21, B21, C21, CHSGND Chassis Ground – Digital and analog ground reference.D21A22, B22, C22, V+ Positive Supply – +18.5 to +25 V.D22A23, D23 +5 V +5 VDC Source – Digital power supply.B23 SPICLK Serial Peripheral Interface (SPI) Clock – Clocks theserial data on the MOSI and MISO lines. Opencollector. I/O.C23 MOSI Master-Out-Slave-In – Transmits data from theSCXIbus to the module. Open collector. I/O.B24 SS* Slot Select – When low, enables modulecommunication over the SCXIbus. Totem pole. Input.* Indicates active low.All other pins are not connected.MOSI, MISO, SPICLK, and SS* form a synchronous communication link that conforms withSPI using an idle-high clock and second-edge data latching. D*/A, INTR*, and RESET* areadditional control signals.When the module is in an SCXI-1000 or SCXI-1001 chassis, the data acquisition board must tapinto the open-collector backplane signal lines via the module rear signal connector as a master towrite to the module. You must set the jumpers to serial mode and configure them for a DIOboard or an MIO board as needed to create this interface. Table 3-1 shows the signal connectionsfrom the rear signal connector to the backplane.
