Keysight / Agilent / HP E1332A 4-Channel Counter/Totalizer

The Keysight E1332A is a 4-channel counter/totalizer VXI module engineered for high-speed counting and signal measurement applications. This B-size, 1-slot register-based device delivers seven distinct counter functions - frequency, period average, pulse width, time interval, totalize, gated totalize, and up/down count - with frequency measurement capability to 4 MHz. The module supports both direct and isolated input configurations, enabling flexible signal conditioning across up to 8 channels via multiplexing between 4 isolated and 4 non-isolated channels, though only 4 channels can totalize simultaneously.

Technical Specifications

Frequency Range: DC to 4 MHz

Input Channels: 4 primary channels; up to 8 channels via multiplexing (4 isolated + 4 non-isolated)

Non-isolated Input Constraints (Channels 1–4): Maximum frequency 4 MHz, minimum 0.002 Hz, maximum time interval/pulse width 858 sec, maximum input ±5 V, minimum sensitivity 25 mVrms at 2 MHz, event detection ±2.5 V, level step size 20 mV

Isolated Input Constraints (Channels 1–4): Maximum frequency 4 MHz, minimum 0.002 Hz, maximum time interval/pulse width 858 sec, maximum input ±42 V, minimum sensitivity 1 Vrms at 2 MHz, event detection ±25 V, level step size 200 mV, isolation 170 Vrms

Totalize Function: Counts rising or falling edge transitions; range 1 to (2³² − 1) counts; minimum pulse width 125 ns

Gated Totalizing: Counts transitions on channels 1 and 3, gated by channels 2 and 4 respectively; programmable gate polarity; range 1 to (2¹⁶ − 1) counts; minimum pulse width 125 ns

Up/Down Counting: Channels 1–2 and 3–4 form paired counters with subtraction logic; range ±(2³¹ − 1); minimum pulse width 125 ns

Digital Input Low-Pass Filter: Software-selectable, 16 binary steps from 4 Hz to 131 kHz; attenuates high-frequency noise including mechanical switch bounce

Key Features

Programmable trigger levels and dual input voltage ranges for signal conditioning

Software-selectable direct or isolated inputs with up to 170 Vrms isolation

Flexible multiplexing between isolated and non-isolated channel pairs

Typical Applications Frequency and time interval measurement, event counting, gated acquisition, and bidirectional pulse accumulation in automated test environments.

Compatibility & Integration VXI form factor enables direct integration into standard VXI mainframes and register-based control architectures.