GE VME-3125A Isolation Scan 12 Bit 32 Channel Analog to Digital Converter Board (6U)

GE VME-3125A Isolation Scan 12 Bit 32 Channel Analog to Digital Converter Board (6U)

Basic Information

Product Name: VME-3125A Isolation Scan 12 Bit 32 Channel Analog to Digital Converter Board (with Built in Testing Function)

Production company: Abaco Systems

Main features

32 single ended or 16 differential inputs

Automatic scanning, continuously digitizing input and storing results in dual port data registers

Input range: Bipolar ± 50mV to ± 10V, Monopolar 0-100mV to 0-10V, or 0 to 25mA current input options

Jumper programmable gains x1, x10, x100

1 12 bit A/D converter with built-in tracking and holding functions

Start scanning without software startup

Pause and lock scanning function, which can achieve 40KSPS arbitrary channel sampling based on channel pointer

Optional A/D range: ± 5V, ± 10V, 0 to+10V

40kHz total conversion rate

Support real-time built-in testing (BIT)

Input connector compatible with discrete and ribbon cables

Optional data encoding: offset binary or binary complement

Over voltage protect

Low pass input filter: 50kHz, optional 40Hz

Pull down resistor to prevent input floating

1000V analog ground/digital ground isolator

Ordering Options

Option Description

A (input option) 0=50kHz input filter (-3dB cut-off frequency, voltage input); 1=40Hz input filter (-3dB cut-off frequency, voltage input); 2=250 Ω 0.01% terminal (high-precision current input); 3=500 Ω 0.01% terminal (high-precision current input)

BCD 0 (reserved for future options)

E (Special Sales Order) 0=Standard; 1=Reserved for CCS

F (conforming coating) 0=standard VME front panel without conforming coating; 1=Reserved; 2=Standard VME front panel with conforming coating; 3=Reserved

Compatible cable connectors

Standard 37 pin ultra small D-type male connector

Discrete cabling: AMP 747916-2 (with 206478-4 enclosure)

Ribbon cable: AMP 747306-1

Functional characteristics

1. Basic Introduction

VME-3125A provides isolated 12 bit analog-to-digital conversion with 32 single ended analog voltage input channels (16 differential) for VMEbus's 6U Eurocard. The optional gain and A/D range support an input voltage range of ± 50mV to ± 10V, and the current input option supports 32 single ended channels with ranges of 0 to 20mA, 4 to 20mA, and 5 to 25mA. To minimize system software overhead, all inputs are continuously scanned and digitized at a total sampling rate of 40000 samples per second, and the measurement data of each channel is accessed by VMEbus at any time through a dual port data register. For voltage input, a 40Hz low-pass input filter can be selected to minimize the impact of system noise, and the standard unit is equipped with a 50kHz low-pass filter.

2. Core functions

Programmable Gain Amplifier (PGA): Jumper options include series voltage gain x1, x10, or x100 for all channels; For voltage input, the full range of the A/D converter can be selected as ± 5V, ± 10V, or 0 to+10V; the data encoding software can be selected as offset binary or binary complement code

Input configuration: The input can be configured with 16 differential voltage channels or 32 single ended voltage or current channels through jumper wires; A single front panel 37 pin ultra small D-type connector provides connections for all input channels

Working mode: All 16 or 32 input channels are continuously scanned at the maximum sampling rate, and the resulting data is stored in a dual port data register for VMEbus to access; After any reset operation, the scan automatically starts without the need for additional programming to initiate the A/D conversion process

Built in Test Function (BIT): By selecting the BIT working mode, the operation of PGA, ADC, and related control logic can be verified. In this mode, the internal reference voltage is applied to the input of PGA, bypassing the analog input multiplexer. All data channels read through the control interface will reflect the selected BIT reference voltage

3. Features related to VMEbus

Compliance: Compliant with VMEbus standard ANSI/IEEE STD 1014-1987, IEC 821 and 297, with 6U external dimensions

Board address: The physical address is selected through the onboard address jumper, using VMEbus address lines A07 to A15; The VME-3125A board occupies 128 bytes of address space and can be located on any 64 word boundary of the short I/O (A16) space

Address Modifier: Address modifier bits are selected and decoded through jumpers to respond to non privileged short I/O access, monitoring short I/O access, or both access privileges

4. System reset and indicator lights

System reset: System reset establishes the following board states: all channels automatically scan, front panel diagnostic LED indicator lights up, offset binary data format

Front panel system diagnostic LED: The software controlled front panel LED lights up when the system is reset and can be turned off under software control to provide an external indication that the built-in test has been completed

Simulate input data format

The analog input is digitized and stored in 32 dual port data registers (16 registers for differential operation) as a 12 bit right aligned digital value. The software can select data codes as offset binary and binary complement. In binary complement encoding, the sign bit (D11) is extended to the most significant bit (D12 to D15) of the data register.