Ametek / VTI Instruments / VXI Technology VM2164 200 MHz, 1nS Universal Counter

The Ametek/VTI Instruments/VXI Technology VM2164 is a 200 MHz universal counter module delivering 1 ns time interval resolution for precision frequency, period, timing, and voltage measurements in automated test systems. This VXIbus-compatible C-size card integrates into VMIP™ platforms, enabling modular instrument configurations while supporting measurement rates exceeding 200 readings per second over the VXIbus or up to 32,000 on-board readings via direct register access.

Technical Specifications

• Frequency (Inputs A & B): 500 µHz to 200 MHz; AC coupled: 20 Hz to 200 MHz; Channel C optional to 2.5 GHz


• Period: 5 ns to 2000 s


• Time Interval: 2 ns to 1e6 s with 1 ns resolution (100 ps with averaging)


• Pulse Width: 5 ns to 20 ms (positive/negative)


• Rise/Fall Time: 10 ns to 1000 s


• Phase: 0.00° to 360.00°


• Gate Time: Programmable 200 µs to 99.999 s


• Voltage Measurement: DC and peak voltage in 5.00 V and 50.0 V ranges Resolution & Performance


• 9-digit resolution at 1 second gate time


• Time interval measurement: 1 ns (100 ps with averaging)


• Reading speed: >200 readings/second over VXIbus; 32,000 on-board readings with register access Input Specifications


• Impedance options: 50 Ω, 1 MΩ // 20 pF, 1 MΩ × 10 // 20 pF


• Trigger sensitivity: +50 V range - 200 mVrms sine (≤50 MHz), 400 mVrms (50–200 MHz); +5.0 V range - 20 mVrms (≤50 MHz), 40 mVrms (50–200 MHz)


• Maximum input voltage: 1 MΩ input 100 kHz: ±5 V to 200 MHz; 50 Ω input: 5.0 Vrms


• Crosstalk: 50 ns pulse width, <250 ns transition time, TTL or ECL voltage levels, ~1 kΩ impedance


• TTL Trigger Bus: Programmable polarity, edge or level selection

Key Features

• VXIbus modular architecture for integrated multi-instrument test systems


• Built-in DVM for voltage measurements


• Multiple totalization modes: count, 2nd channel start/stop, 2nd channel gate, time gate, external arm


• High-speed data buffering: 32,000 on-board readings


• Flexible input coupling and impedance selection

Typical Applications

• Frequency and timing validation in RF and digital circuits


• Production test environments requiring high-speed measurement throughput


• Automated test equipment with modular instrument integration


• Phase and pulse characterization in signal analysis

Compatibility & Integration VXIbus C-size module compatible with VMIP™ instrument platforms, enabling single-chassis multi-function test configurations with standardized VXI backplane communication.