Introduction
The VMIVME-3122 is a member of VMIC’s extensive family of analog input/output  products for the VMEbus. With 16-bit digitizing resolution, program-controlled gain,
selectable conversion rate, and automatic scanning of 64 differential or single-ended analog inputs, the VMIVME-3122 provides exceptional dynamic range and analog
input channel density. Various operating modes are supported, including autoscanning, data bursts and external synchronization. This board is designed to
interface directly with VMIC’s line of signal conditioning boards for digitizing the outputs from thermocouples, RTDs and strain gages.
Individual channel gains can be downloaded for use during scanning operations, or the board can be configured with a fixed gain that is common to all channels.
Multiple boards can be synchronized together to enable as many as 16 boards to initiate each scan simultaneously. An Interval Timer, Bus Interrupter, Channel
Counter and Midscan/Endscan flag simplify the monitoring of data within the dual port data buffer. The system applications that can benefit from the VMIVME-3122
capabilities include factory automation, process control, data acquisition systems, training simulators and laboratory instrumentation.
The following brief overview of principal features illustrates the flexibility and performance that is available with the VMIVME-3122:
• 16, 32 or 64 differential or single-ended analog inputs
•16-bit A/D conversion
• 381 Hz to 100 kHz selectable scanning rate for high-performance option, 381 Hz
to 50 kHz for standard performance option
• Programmable gains of x1 or x10

Features of the VMIVME-3122 (Continued):
• A/D converter ranges of ±2.5 V, ±5 V, ±10 V, 0 to +5 V, 0 to +10 V
• Programmable channel gains
• 16- to 1,024-word dual port data buffer
• Operation in short I/O (A16), standard (A24), or extended (A32) data space
• Programmable channel block size and buffer size
• Optional low pass input filters
• Continuous and burst operating modes
• Free running operation or external/internal triggering
• Bus interrupter for Midscan or Endscan indication
• Programmable interval timer for timed data bursts
• Direct cabling from VMIC signal conditioning boards
• Initializes after a reset in autoscan mode with gain = x