National Instruments NI 783xR User Manual

Also see for NI 783xR: User manual User manual

Contents

National Instruments NI 783xR User Manual Manual pdf 37 page image

Chapter 2 Hardware Overview of the NI 783xRNI 783xR User Manual 2-18 ni.comsignals or non-edge-sensitive, low-frequency digital signals. Examples ofhigh-frequency or edge-sensitive signals include clock, trigger, pulse-widthmodulation (PWM), encoder, and counter signals. Examples of staticsignals or non-edge-sensitive, low-frequency signals include LEDs,switches, and relays. Table 2-4 summarizes these guidelines.RTSI Trigger BusThe NI 783xR can send and receive triggers through the RTSI trigger bus.The RTSI bus provides eight shared triggers lines that connect to all thedevices on the bus. In PXI, the trigger lines are shared between all the PXIslots in a bus segment. In PCI, the RTSI bus is implemented through aribbon cable connected to the RTSI connector on each device that needs toaccess the RTSI bus.You can use the RTSI trigger lines to synchronize the NI 783xR to any otherdevice that supports RTSI triggers. On the NI PCI-783xR, the RTSI triggerlines are labeled RTSI/TRIG<0..6> and RTSI/OSC. On the NI PXI-783xR,the RTSI trigger lines are labeled PXI/TRIG<0..7>. In addition, theNI PXI-783xR can use the PXI star trigger line to send or receive triggersfrom a device plugged into Slot 2 of the PXI chassis. The PXI star triggerline on the NI PXI-783xR is PXI/STAR.The NI 783xR can configure each RTSI trigger line either as an input or anoutput signal. Because each trigger line on the RTSI bus is connected inparallel to all the other RTSI devices on the bus, only one device shoulddrive a particular RTSI trigger line at a time. For example, if oneNI PXI-783xR is configured to send out a trigger pulse on PXI/TRIG0,the remaining devices on that PXI bus segment must have PXI/TRIG0configured as an input.Table 2-4. DIO Signal Guidelines for the NI 783xRDigital LinesSH68-C68-S Shielded CableSignal PairingRecommended Typesof Digital SignalsConnector 0, DIO<0..7>;Connector 1, DIO<0..27>;Connector 2, DIO<0..27>DIO line paired with poweror groundAll types—high-frequency orlow-frequency signals,edge-sensitive ornon-edge-sensitive signalsConnector 0, DIO<8..15>;Connector 1, DIO<28..39>;Connector 2, DIO<28..39>DIO line paired with anotherDIO lineStatic signals ornon-edge-sensitive,low-frequency signals