Overview

The VM4018 is a high-performance analog comparator module with sixteen input channels per VMIP™ daughter module.

Each input channel can be programmed for the following ranges: ±1 V, ±2.5 V, ±10 V, ±25 V, ±100 V, and ±250 V. Each input is compared against a reference voltage derived from an independent 12-bit DAC. The VM4018 is an ideal device in go/no-go testing where a device fails if the voltage outputs exceed a threshold or window, or even in control applications if a device or test needs to be shut down if a voltage level is exceeded. Using an analog comparator/interrupter in certain applications, as opposed to a traditional DMM/switch approach, considerably improves the overall throughput of the test, while substantially reducing cost.Each input signal is digitally debounced for a programmed time ranging from approximately 12.8 µs to 0.42 s. This prevents input signal noise from causing undesired interrupts. After debounce, the signal may be inverted via serial word command to select the input transition edge of interest (rising or falling edge) and masked to prevent unused channels from causing interrupts.

The VM4018 is part of the VMIP™ family of instruments and can be combined with up to two other modules to form a high-density VXIbus instrument that fully utilizes the capabilities of the VMIP™. For example, when combined with the VM1602 Time Stamp, all analog interrupts can be time stamped.