Configuration and Installation Chapter 2SCXI-1160 User Manual 2-17 © National Instruments CorporationRear Signal Connector Signal DescriptionsPin Signal Name Description24 or 50 DIG GND Digital Ground – Supplies the reference for dataacquisition board digital signals and is tied to themodule digital ground. Pin 50 is for DIO typeboards. Pin 24 is for MIO type boards and jumperW3 selects it.25 SERDATIN Serial Data In – Taps into the SCXIbus MOSI lineto provide serial input data to a module or Slot 0.26 or 47 SERDATOUT Serial Data Out – Taps into the SCXIbus MISO lineto accept serial output data from a module. Pin 47is for DIO type boards. Pin 26 is for MIO typeboards and jumper W2 selects it.27 DAQD*/A Data Acquisition Board Data/Address Line – Tapsinto the SCXIbus D*/A line to indicate to themodule whether the incoming serial stream is dataor address information.29 SLOT0SEL* Slot 0 Select – Taps into the SCXIbus INTR* lineto indicate whether the information on MOSI issent to a module or to Slot 0.31 or 37 SERCLK Serial Clock – Taps into the SCXIbusSPICLK line to clock the data on the MOSI andMISO lines. Pin 31 is for DIO boards. Pin 37 is forMIO boards and jumper W4 selects it.All other pins are not connected.See the Timing Requirements and Communication Protocol section later in this chapter for moredetailed information on timing.The signals on the rear signal connector are digital I/O signals. Signal connection guidelines foreach of these groups are given in the following section.Digital I/O Signal ConnectionsPins 24 through 27, 29, 31, 37, 47, and 50 constitute the digital I/O lines of the rear signalconnector. They are divided into three categories–the digital input signals, the digital outputsignals, and the digital timing signals.The digital input signals are pins 24 or 50, 25, 27, 29, and 31 or 37. The data acquisition boarduses these pins to configure the SCXI module that the data acquisition board controls.
