Page 4
Instruments Corporation. National Instruments respects the intellectual property of others, and we ask our users to do the same. NI software is protected by copyright and other intellectual property laws. Where NI software may be used to reproduce software or other materials belonging to others, you may use NI software only to reproduce materials that you may reproduce in accordance with the terms of any applicable license or other legal restriction.
Page 5
These classes are known as Class A (for use in industrial-commercial locations only) or Class B (for use in residential or commercial locations). All National Instruments (NI) products are FCC Class A products. Depending on where it is operated, this Class A product could be subject to restrictions in the FCC rules. (In Canada, the Department of Communications (DOC), of Industry Canada, regulates wireless interference in much the same way.) Digital...
Page 7
Contents Chapter 3 Signal Connections Programmable Function Interfaces (PFIs)..............3-1 Digital Filtering ......................3-1 Power-On State......................3-3 Pin Assignments ......................3-4 I/O Connector Pinout..................... 3-6 Outputs .......................... 3-8 Counters......................... 3-10 Counter n Source Signal ................. 3-10 Counter Source to Counter Out Delay..........3-12 Counter n Gate Signal ..................
NI-DAQ 7.x software and the DAQ device, and how to confirm that the device is operating properly. • NI-DAQmx Help—This help file contains information about using NI-DAQmx to program National Instruments devices. NI-DAQmx is the software you use to communicate with and control your DAQ device. •...
The NI 660x devices contain the National Instruments MITE PCI interface. The MITE offers bus-master operation, PCI burst transfers, and high-speed DMA controller(s) for continuous, scatter-gather DMA without requiring DMA resources from your computer.
Chapter 1 Introduction The specification permits vendors to develop sub-buses that coexist with the basic PCI interface on the bus. Compatible operation is not guaranteed between devices with different sub-buses nor between devices with sub-buses and PXI. The standard implementation for does not include these sub-buses.
Chapter 2 Device Overview Figure 2-1 shows an example of prescaling. External Signal Prescaler Rollover (Used as Source by Counter) Counter Value Figure 2-1. Prescaling Example Prescaling is intended for use with two counter period and frequency measurements where the measurement is made on a continuous, repetitive signal.
Chapter 2 Device Overview Example Application That Works Incorrectly (Duplicate Counting) In Figure 2-5, after the first rising edge of Gate, no Source pulses occur. So the counter does not write the correct data to the buffer. No Source edge, so no value written to buffer.
Chapter 2 Device Overview Transfer Rates The maximum sustainable transfer rate a TIO device can achieve for a buffered acquisition depends on the following factors: • Amount of available bus bandwidth • Processor speed and operating system • Application software To reduce the amount of bus activity, limit the number of devices generating bus cycles.
VCXO 80 MHz Phase Locked to Clock 10 MHz PXI Backplane Clock Phase Lock 10 MHz PXI Backplane Clock Loop NI PXI-6608 or NI PXI-6602 in Slot 3 of PXI Chassis TIO(0) PXI Star (Not Used 10 MHz OCXO Backplane...
NI 660X Register-Level Programmer Manual, available from ni.com/manuals The National Instruments Measurement Hardware DDK provides development tools and a register-level programming interface for NI data acquisition hardware. The NI Measurement Hardware DDK provides access to the full register map of each device and offers examples for completing common measurement and control functions.
Page 27
Chapter 3 Signal Connections between two consecutive rising edges of the filter clock timebase. The frequency of the filter clock timebase determines whether a transition in the signal may propagate or not. The function of the internal sampling clock is to increase the sampling rate and prevent aliasing.
Chapter 3 Signal Connections Pin Assignments Table 3-2 lists the pin assignments for the I/O connector on the NI 660x. Note The NI 6601 uses counters <0..3> only. Table 3-2. NI 660x Connector Pin Assignments Motion Counter Counter Motion Signal Encoder Context Context...
Chapter 3 Signal Connections I/O Connector Pinout Figure 3-2 shows the pin assignments for the I/O connectors on the NI 660x. Note The NI 6601 uses counters <0..3> only. NI 660x User Manual ni.com...
Chapter 3 Signal Connections Outputs PFI <0..7> are used for DIO only. PFI <32..39> are used for counters and motion encoders only. You can use PFI <8..31> as either of the three choices. When used as an output, you can individually configure each PFI line as a DIO line or a counter line (you need not distinguish between counter/encoder or DIO applications when you use a PFI line as an input).
The maximum frequency you can drive at the I/O connector is affected by the capacitive load your cable presents. You can achieve 40 MHz output with a National Instruments 1 m SH68-68-D1 shielded cable (capacitive load = 80 pF). At larger loads, your maximum output frequency may be lower.
Chapter 3 Signal Connections Counter Source to Counter Out Delay Figure 3-4 shows the CtrnSource to CtrnInternalOutput delay. CtrnSource CtrnInternalOutput Figure 3-4. CtrnSource to CtrnInternalOutput Delay Figure 3-4 shows the delay between the active edge of the CtrnSource signal and the active edge of the CtrnInternalOutput signal. In the figure, the CtrnSource and CtrnInternalOutput signals are active high.
Chapter 3 Signal Connections Counter n Auxiliary Signal You can select any PFI or RTSI, as well as many other internal signals as the Counter n Auxiliary (CtrnAux) signal. Much like this CtrnGate signal, the CtrnAux signal is configured in edge-detection or level-detection mode depending on the application performed by the counter.
NI-DAQmx Help, and/or use the examples that are available with NI-DAQmx. Real-Time System Integration Bus TIO devices use the National Instruments Real-Time System Integration (RTSI) bus to easily synchronize several measurement functions to a common trigger or timing event. In a PCI system, the RTSI bus consists of the RTSI bus interface and a ribbon cable.
Do not connect the +5 V power pin directly to D GND, RG, or any pin configured for output on the NI 660x device, or any voltage source or output pin on another device. Doing so can damage the device and the computer. National Instruments is not liable for damages resulting from such a connection.
Chapter 3 Signal Connections Crosstalk Crosstalk mainly occurs when the capacitance between lines in a cable induces a smaller transition on another line. Figure 3-9 shows an example of crosstalk. Cable PFI 11 Capacitance PFI 10 PFI 10 PFI 11 Figure 3-9.
Page 47
Chapter 3 Signal Connections Table 3-9 lists the signals and the D GND pin number on the 68-pin connector block. Table 3-9. Signals and D GND Pin Number on 68-Pin Connector Block PFI Number Pin Number for D GND PFI 0 PFI 1 PFI 2 PFI 3...
Page 49
Chapter 3 Signal Connections For reflection problems that occur when the NI 660x receives the signal, use series termination at the device driving the signal. The sum of R and the output impedance of the source is approximately 80 W. Typically, this condition results in a value of approximately 50 W for R .
Technical Support and Professional Services Visit the following sections of the National Instruments Web site at for technical support and professional services: ni.com • Support—Online technical support resources at ni.com/support include the following: – Self-Help Resources—For answers and solutions, visit the...
Page 51
Appendix A Technical Support and Professional Services • Calibration Certificate—If your product supports calibration, you can obtain the calibration certificate for your product at ni.com/calibration If you searched and could not find the answers you need, contact ni.com your local office or NI corporate headquarters. Phone numbers for our worldwide offices are listed at the front of this manual.
Page 53
Glossary asynchronous A property of an event that occurs at an arbitrary time, without synchronization to a reference clock. bit—one binary digit, either 0 or 1. byte—eight related bits of data, an eight-bit binary number. Also used to denote the amount of memory required to store one byte of data. base address A memory address that serves as the starting address for programmable registers.
Page 54
DIO boards plugged into a computer, and possibly generating control signals with D/A and/or DIO boards in the same computer. DAQ-STC A custom ASIC developed by National Instruments that provides timing information and general-purpose counter/timers on National Instruments E Series boards.
Page 55
Glossary direct memory access—a method by which data can be transferred to/from computer memory from/to a device or memory on the bus while the processor does something else. DMA is the fastest method of transferring data to/from computer memory. driver Software that controls a specific hardware device such as a DAQ board.
Page 57
Glossary MITE A custom ASIC designed by National Instruments that implements the PCI bus interface. The MITE supports bus mastering for high speed data transfers over the PCI bus. motion encoders Transducers that generate pulses to indicate the physical motion of a device.
Page 58
The oscillation of a signal about a high-voltage or low-voltage state immediately following a transition to that state. RTSI Bus real-time system integration bus—the National Instruments timing bus that connects DAQ boards directly, by means of connectors on top of the boards, for precise synchronization of functions.
Page 59
Glossary start trigger A TTL level signal having two discrete levels, a high and a low level, that starts an operation. synchronous A property of an event that is synchronized to a reference clock. terminal count—a strobe that occurs when a counter reaches zero from either direction.
Need help?
Do you have a question about the PXI-6602 and is the answer not in the manual?
Questions and answers