PCI-6602 8-Channel 32-Bit Counter/Timer Device
The PCI-6602 is a high-performance counter/timer device for conventional PCI computers. It provides eight independent 32-bit counter/timers and 32 TTL/CMOS-compatible digital I/O lines for event counting, encoder measurements, frequency analysis and pulse generation.
The device uses NI-TIO counter/timer technology and includes 100 kHz, 20 MHz and 80 MHz internal timebases. It can measure input frequencies up to 80 MHz without prescaling and supports higher-frequency event counting through its selectable prescalers.
Three simultaneous high-speed DMA transfers help the PCI-6602 perform buffered counter measurements without depending entirely on software polling. Digital debounce filters, flexible signal routing and NI-DAQmx support make it suitable for automated test, motion monitoring, manufacturing and laboratory timing applications.
Key Features of the PCI-6602
- Eight independent 32-bit counter/timers
- 32 static TTL/CMOS-compatible digital I/O lines
- 80 MHz maximum source frequency without prescaling
- Up to 125 MHz source frequency with prescaling
- 100 kHz, 20 MHz and 80 MHz internal timebases
- 50 ppm base-clock accuracy over temperature
- Maximum counter value of 4,294,967,295
- Event and edge counting
- Frequency and period measurement
- Pulse-width and pulse-separation measurement
- Quadrature encoder position measurement
- Pulse and pulse-train generation
- Digital debounce filtering
- Three simultaneous high-speed DMA transfers
- 68-pin SCSI-type front connector
- NI-DAQmx software support
PCI-6602 Technical Specifications
| Product Model | PCI-6602 |
|---|---|
| Primary Part Number | 777531-01 |
| Hardware-Only Kit Part Number | 184479-01 |
| Product Type | PCI counter/timer and digital I/O device |
| Number of Counter/Timers | 8 |
| Counter Resolution | 32 bits |
| Counter Operation | Up/down counting |
| Maximum Counter Value | 4,294,967,295 |
| Internal Timebases | 100 kHz, 20 MHz and 80 MHz |
| Base-Clock Accuracy | 50 ppm, ±0.005%, over temperature |
| Maximum Source Frequency | 80 MHz without prescaling |
| Maximum Frequency with Prescaling | 125 MHz |
| Counter Prescalers | ×2 or ×8, selectable for each counter |
| DMA Channels | 3 simultaneous high-speed DMA transfers |
| Digital I/O Channels | 32 |
| Digital I/O Transfer Type | Static, software-timed |
| Digital Logic Compatibility | 5 V TTL/CMOS |
| Digital Input Range | -0.3 V to 5.5 V |
| Input Filtering | Programmable digital debounce filters |
| Front Connector | 68-pin, 0.050-inch D-type SCSI connector |
| Bus Interface | Conventional PCI |
| Operating Temperature | 0°C to 55°C |
| Software Support | NI-DAQmx |
| Recommended Replacement | PCIe-6612, part number 782351-01 |
PCI-6602 Part Numbers and Accessories
| Item | Part Number | Description |
|---|---|---|
| PCI-6602 | 777531-01 | Eight-channel, 32-bit PCI counter/timer device with 32 digital I/O lines |
| PCI-6602 Hardware-Only Kit | 184479-01 | Hardware-only configuration of the PCI-6602 |
| SH68-68-D1 Cable | 183432-01 | 1 m shielded 68-pin digital I/O cable |
| SH68-68-D1 Cable | 183432-02 | 2 m shielded 68-pin digital I/O cable |
| SCB-68A Connector Block | 782536-01 | Shielded, noise-rejecting 68-pin screw-terminal connector block |
| BNC-2121 Connector Block | 778289-01 | BNC connectivity accessory designed for counter/timer signals |
| TBX-68 Connector Block | 777141-01 | DIN-rail-mount 68-pin screw-terminal connector block |
| CB-68LP Connector Block | 777145-01 | Low-cost vertical-mount 68-pin terminal block |
| CB-68LPR Connector Block | 777145-02 | Low-cost right-angle 68-pin terminal block |
| R68-68 Cable | 182482-01 | 1 m low-cost unshielded 68-pin ribbon cable |
The SH68-68-D1 is the recommended shielded cable for the PCI-6602. Its conductor arrangement pairs digital signals with digital ground to reduce noise and crosstalk. Select the terminal block according to whether the system requires screw terminals, BNC connectors, DIN-rail installation or custom fixture wiring.
Eight Independent 32-Bit Counter/Timers
The PCI-6602 contains eight hardware counter/timers. Each counter can count upward or downward and has a maximum count value of 4,294,967,295.
The counters can perform separate measurement and generation operations. For example, one counter can measure an encoder while another counts production events and additional counters generate test pulses.
Actual resource use depends on the selected task. Certain operations, including some finite pulse-train configurations, may use a paired counter internally. Review the NI-DAQmx task configuration when several complex counter operations must run at the same time.
80 MHz Counter Timebase
The PCI-6602 provides an 80 MHz internal timebase with a nominal period of 12.5 ns. This high-speed clock improves the resolution of frequency, period, pulse-width and pulse-generation applications.
It also provides 20 MHz and 100 kHz timebases. Software can select the most appropriate timing source according to the required measurement range, resolution and maximum count duration.
| Timebase | Nominal Period | Approximate 32-Bit Rollover Time |
|---|---|---|
| 100 kHz | 10 µs | 11.93 hours |
| 20 MHz | 50 ns | 214.74 seconds |
| 80 MHz | 12.5 ns | 53.69 seconds |
High-Frequency Event Counting
The PCI-6602 supports source frequencies up to 80 MHz without prescaling. Each counter also includes selectable ×2 and ×8 prescalers that permit event counting at frequencies up to 125 MHz under the applicable signal and timing conditions.
Prescaling divides the incoming event stream before it reaches the counter. This extends the supported input frequency but prevents the system from identifying every individual edge directly. Prescaling should therefore be selected only when its effect is compatible with the measurement.
Frequency Measurement
The device can measure signal frequency using counter-based methods such as period measurement, reciprocal counting and buffered edge counting. The most appropriate method depends on the expected frequency range, required update rate and desired resolution.
High-frequency signals benefit from the 80 MHz timebase, while lower-frequency signals may require longer measurement intervals to achieve stable results. Proper grounding and signal integrity become increasingly important as input frequency rises.
Period and Pulse-Width Measurement
The PCI-6602 can measure the time between input edges to determine signal period. It can also measure how long a signal remains high or low, making it suitable for pulse-width, duty-cycle and timing verification.
Typical applications include testing digital control signals, monitoring sensor pulse duration, checking actuator timing and characterizing pulse-based communication or control circuits.
Encoder Position Measurement
The counter/timers support quadrature encoder measurements for tracking rotational or linear position. The device can decode phase A and phase B signals and use an index signal when required by the application.
Encoder measurements are useful for motors, machine tools, positioning stages, conveyors and manufacturing equipment. Correct configuration of encoder type, counting direction, pulses per revolution and mechanical scaling is necessary to convert counter values into engineering units.
Event and Production Counting
The PCI-6602 can count pulses generated by proximity sensors, optical sensors, switches and other TTL-compatible sources. Hardware counting allows short events to be captured without relying on the operating system to detect every transition.
Applications include counting manufactured parts, monitoring machine cycles, measuring shaft revolutions and recording test events. Digital filtering can be applied when contact bounce or electrical interference creates unwanted transitions.
Pulse and Pulse-Train Generation
The counters can generate single pulses, continuous pulse trains and supported finite pulse sequences. Programmable high and low times allow software to control output frequency and duty cycle.
Pulse generation can be used to simulate sensors, clock external instruments, trigger test equipment, control stepper interfaces and verify digital circuits. Confirm that the receiving device is compatible with the PCI-6602 TTL voltage levels.
Digital Debounce Filters
Programmable digital filters help reject short input disturbances caused by switch bounce, electromagnetic interference or noisy cabling. Filtering is particularly useful with mechanical switches, encoders and sensors installed in industrial environments.
A filter should be long enough to reject unwanted pulses but short enough to preserve the shortest valid input event. Excessive filtering can delay or completely suppress legitimate high-speed transitions.
Three Simultaneous DMA Transfers
The PCI-6602 supports three simultaneous high-speed DMA transfers. DMA allows buffered counter data to move directly between the device and computer memory with less processor involvement than software-controlled transfers.
If more than three buffered counter operations run simultaneously, additional tasks may use interrupt-based transfers depending on driver configuration and available resources. Test throughput should be verified using the intended computer, operating system and software workload.
32 TTL/CMOS Digital I/O Lines
In addition to the eight counter/timers, the PCI-6602 provides 32 TTL/CMOS-compatible digital I/O lines. These lines can monitor logic states or control low-current digital signals associated with the timing application.
The general-purpose digital lines are static and software-timed. They are not a substitute for a hardware-timed digital waveform device. Counter terminal routing can also use some connector lines, so the number available for general-purpose I/O depends on the active counter configuration.
Flexible Signal Routing
The NI-TIO architecture allows counter source, gate, auxiliary and output signals to be routed through supported PFI terminals. This flexibility reduces external rewiring when the same hardware performs different measurement tasks.
Routing availability depends on the selected counter and terminal. Verify the PCI-6602 pinout and NI-DAQmx routing configuration before assigning signals in a multi-counter system.
TTL Signal Compatibility
The PCI-6602 is intended for 5 V TTL/CMOS digital signals. It is not an isolated industrial 24 V input device, and 12 V or 24 V signals must not be connected directly to its terminals.
Use external level conversion, isolation or signal conditioning when interfacing with higher-voltage encoders, sensors or programmable logic controllers. All external signals must remain within the specified electrical range.
Typical PCI-6602 Applications
- Quadrature encoder position measurement
- Motor and shaft-speed measurement
- High-speed event counting
- Frequency and period measurement
- Pulse-width and duty-cycle measurement
- Pulse and pulse-train generation
- Production-part counting
- Machine-cycle monitoring
- Stepper-control timing
- Automated test equipment
- Digital timing validation
- Laboratory experiment automation
- Sensor simulation
- Legacy PCI system maintenance
Motion and Encoder Applications
The PCI-6602 can measure several encoder channels within one computer-based system. This is useful for monitoring multiple motors, shafts or linear axes without installing a separate measurement device for each encoder.
The board measures encoder feedback but is not a complete safety-rated motion controller. Applications requiring closed-loop motion control, drive communication or machine safety may require additional controller and protection hardware.
Automated Test Systems
In automated test equipment, the PCI-6602 can generate repeatable stimulus pulses and measure the timing response of a device under test. Multiple counters allow different timing operations to run within the same test sequence.
The device can be combined with NI PCI and USB data acquisition hardware for systems that also require analog voltage, temperature or additional digital measurements.
NI-DAQmx Software Support
The PCI-6602 is controlled through the NI-DAQmx driver. NI-DAQmx provides functions for creating counter input, counter output and static digital I/O tasks, selecting terminals, configuring timing and transferring acquired data.
Supported development environments include LabVIEW, LabWindows/CVI, C, C++ and compatible .NET languages. NI Measurement & Automation Explorer can be used to confirm device recognition, inspect pinouts and test basic counter operation.
PCI Computer Compatibility
The PCI-6602 requires a conventional PCI expansion slot. A PCI Express slot is mechanically and electrically different and cannot accept the PCI-6602 directly.
Before ordering, verify the computer’s available slot type, operating-system support and compatible NI-DAQmx version. The PCIe-6612 is NI’s recommended replacement when a modern PCI Express interface is required.
PCI-6602 Cable and Connector Selection
The board uses a 68-pin SCSI-type connector. The recommended SH68-68-D1 cable is specifically arranged for digital signals and should be preferred over visually similar 68-pin cables with different internal conductor pairings.
The SCB-68A is appropriate when shielded screw-terminal connectivity and improved noise rejection are required. The BNC-2121 provides convenient BNC access for counter/timer signals, while the TBX-68 supports DIN-rail installations.
PCI-6602 Troubleshooting
The PCI-6602 is not detected in NI MAX
Confirm that the device is fully inserted into a conventional PCI slot. Check the computer firmware, operating-system device list and NI-DAQmx installation, then restart the computer and rescan for hardware.
The counter does not detect input pulses
Verify the selected physical terminal, signal ground and counter source configuration. Measure the input waveform to confirm that it satisfies the PCI-6602 TTL voltage and pulse-width requirements.
The event count is higher than expected
Inspect the input for contact bounce, ringing, electromagnetic noise or improper termination. Enable a suitable digital debounce filter and improve grounding or shielding when necessary.
The event count is lower than expected
Confirm that the input frequency and minimum pulse width remain within specification. Check whether the selected digital filter is suppressing valid pulses and whether prescaling has been enabled.
The measured frequency is unstable
Check the signal amplitude, edge quality, grounding and cable shielding. Increase the measurement interval for low-frequency signals or select a measurement method better suited to the expected frequency range.
An encoder counts in the wrong direction
Reverse the phase A and phase B connections or modify the counting-direction configuration. Confirm the encoder wiring and decoding mode before changing mechanical scaling.
A generated pulse train has the wrong frequency
Review the selected timebase, high-time and low-time values. Include counter quantization in the calculation because the requested timing values must be represented by whole timebase periods.
A finite pulse train uses an additional counter
Certain PCI-6602 finite pulse-train operations use an adjacent paired counter internally. Check counter resource allocation and move conflicting tasks to another counter when necessary.
More than three buffered tasks cannot use DMA
The PCI-6602 provides three simultaneous DMA channels. Additional buffered operations may need interrupt-based transfers, depending on the driver and task configuration.
The digital I/O does not produce a hardware-timed waveform
The 32 general-purpose digital I/O lines are static and software-timed. Use the counter outputs for supported pulse generation or select a dedicated hardware-timed digital I/O device for arbitrary digital waveforms.
PCI-6602 Comparison with Similar Counter/Timer Devices
| Model | Counter Configuration | Bus | Best Suited For |
|---|---|---|---|
| PCI-6602 | 8 counters, 32 bits, 80 MHz | PCI | High-performance timing in legacy PCI computers |
| PCI-6601 | 4 counters, 32 bits, 20 MHz | PCI | Lower-channel-count PCI timing applications |
| PCIe-6612 | 8 counters, 32 bits, 80 MHz | PCI Express | Modern computer-based counter/timer systems |
| PXI-6602 | 8 counters, 32 bits, 80 MHz | PXI | Modular PXI timing and automated test systems |
| PXI-6608 | 8 counters with high-stability timing | PXI | PXI applications requiring improved timing accuracy |
| PXI-6624 | 8 isolated industrial counters | PXI | Higher-voltage industrial counter interfaces |
PCI-6602 vs PCI-6601
The PCI-6602 provides eight 32-bit counters and an 80 MHz timebase, while the PCI-6601 provides four counters and a 20 MHz timebase. The PCI-6602 therefore supports more simultaneous timing tasks and higher measurement resolution.
Choose the PCI-6601 when four counters and lower input frequencies are sufficient. Select the PCI-6602 when the application requires eight counters, 80 MHz timing or additional high-speed counter capacity.
PCI-6602 vs PCIe-6612
The PCI-6602 and PCIe-6612 provide similar eight-counter functionality, but they use different computer buses. The PCI-6602 uses conventional PCI, whereas the PCIe-6612 uses PCI Express.
The PCI-6602 is appropriate for maintaining an existing PCI test system. The PCIe-6612 is the recommended replacement for newer computers and is the better choice when designing a new counter/timer system.
PCI-6602 vs PXI-6602
The PCI-6602 installs in a desktop or industrial computer, while the PXI-6602 is designed for a PXI chassis. Their counter/timer capabilities are similar, but the physical platform and system-integration architecture differ.
Choose the PCI version for a computer-based system with an available PCI slot. Choose the PXI version when the timing device must operate with other modular PXI instruments in a synchronized test platform.
Recommended Related Products
- PCIe-6612 8-Channel PCI Express Counter/Timer Device
- PCI-6601 4-Channel PCI Counter/Timer Device
- PXI-6602 8-Channel PXI Counter/Timer Module
- PXI-6608 High-Stability Counter/Timer Module
- PXI-6624 Isolated Industrial Counter/Timer Module
- View More NI PCI and USB Data Acquisition Products
- View More NI PXI and PXI Express Modules
Selecting the Right Counter/Timer Device
Choose the PCI-6602 when an existing conventional PCI system requires eight 32-bit counters, an 80 MHz timebase, encoder measurements and multiple buffered counter operations.
Select the PCIe-6612 for new computer-based systems with PCI Express slots. Consider the PXI-6602 when modular PXI integration is required, or the PXI-6624 when the application needs isolated industrial-level counter inputs.
Why Choose the PCI-6602?
- Provides eight independent 32-bit counter/timers
- Supports event, frequency, period and pulse measurements
- Measures quadrature encoder position
- Generates pulses and programmable pulse trains
- Includes a high-resolution 80 MHz timebase
- Supports high-frequency counting with prescalers
- Performs three simultaneous DMA transfers
- Provides 32 additional static digital I/O lines
- Includes programmable digital debounce filters
- Integrates with NI-DAQmx and LabVIEW
Frequently Asked Questions
What is the PCI-6602?
The PCI-6602 is a conventional PCI counter/timer device with eight 32-bit counters and 32 TTL/CMOS-compatible digital I/O lines.
What is the standard PCI-6602 part number?
The established NI product part number is 777531-01. NI also identifies 184479-01 as a PCI-6602 hardware-only kit configuration.
How many counters does the PCI-6602 provide?
It provides eight independent 32-bit up/down counter/timers.
What is the maximum counter value?
Each 32-bit counter can represent values from 0 through 4,294,967,295 before rollover.
What internal timebases are available?
The PCI-6602 provides 100 kHz, 20 MHz and 80 MHz internal timebases.
What is the maximum input frequency?
The maximum source frequency is 80 MHz without prescaling and up to 125 MHz when a supported prescaler is used.
Can the PCI-6602 measure quadrature encoders?
Yes. It supports quadrature encoder position measurement using phase A, phase B and an optional index signal.
Can the PCI-6602 generate pulse trains?
Yes. Its counter outputs can generate single pulses, continuous pulse trains and supported finite pulse sequences.
Are the 32 digital I/O lines hardware timed?
No. The general-purpose digital I/O lines are static and software-timed. Hardware-timed pulse generation is performed by the counter outputs.
How many DMA transfers can run simultaneously?
The PCI-6602 supports three simultaneous high-speed DMA transfers.
Does the PCI-6602 accept 24 V industrial signals?
No. It is designed for 5 V TTL/CMOS signals. Higher-voltage industrial signals require external isolation or level conversion.
Which cable is recommended for the PCI-6602?
NI recommends the shielded SH68-68-D1 cable. Part number 183432-01 is the 1 m version, while 183432-02 is the 2 m version.
Which terminal blocks are compatible?
Compatible options include the SCB-68A, BNC-2121, TBX-68, CB-68LP and CB-68LPR.
What is the recommended replacement for the PCI-6602?
NI identifies the PCIe-6612, part number 782351-01, as the recommended PCI Express replacement.
Request a Quote for the PCI-6602
Contact us for current availability, condition, lead time and project pricing for the PCI-6602 8-Channel 32-Bit Counter/Timer Device. We can also help identify compatible SH68-68-D1 cables, SCB-68A terminal blocks and replacement PCIe or PXI counter/timer hardware.
