GE VMIVME-4140 32-Channel 12-Bit Analogue Output Boards

Functionality

The VMIVME-4140 Analogue Output Board provides 32 high quality analogue output channels with 12-bit resolution, capable of outputting or sinking 10 mA at ±10 V. The outputs all have a dedicated D/A converter (DAC).

The outputs each have a dedicated D/A converter (DAC).

The analogue outputs can be disconnected from the field wiring for off-line testing. Calibration and self-test are initiated by a VMEbus system reset or by executing a software command.

During calibration, offset and gain factor tables are compiled and stored in RAM. Each of the 32 channels configured over the six output voltage ranges has a corresponding offset and gain.

Self-Test: A self-test is run automatically after a system reset.

The self-test register indicates success or failure and can display the channel that failed.

Front Panel Status LEDs: The LEDs illuminate after a system reset. After a successful self-test and auto-calibration, the LED is off. The LED can also be turned on or off under software control.

Functions

- 32 analogue output channels

- Maximum output current per channel is 10mA.

- One 12-bit D/A converter (DAC) per output channel

- 0.8Ω output impedance

- Random update (non-scanning)

- Software or external synchronised update of double buffered outputs

- Single reference potentiometer - no additional manual calibration required

- Auto-calibration initiated by reset or software command

- Unipolar (0 to +10V, 0 to +5V, 0 to +2.5V) or bipolar (±2.5. ±5 and ±10V) software selectable

- Discrete or bulk terminated cables

- Self-testing

- Extensive on-board diagnostic test capabilities

- Outputs can be disconnected from the field for off-line operation

- PMC expansion slots

- Self-test

- Front panel status LEDs

- Front panel analogue output connector

- Front panel reference voltage access

- Applications

- Data acquisition systems

- Control systems

- Precision analogue stimulus

- Automatic Test Equipment (ATE)

Front Panel Reference Voltage Access: Isolated BNC connectors on the front panel allow access to the internal reference voltage. The front panel allows the reference voltage to be adjusted accordingly.

Calibration: When auto-calibration is initiated via system reset or software command, the embedded DSP loads the calibrated output values into each output DAC and then reads them back to the DSP via a 16-bit ADC.

This is repeated until a sufficient number of calibration points have been measured. A calibration table consisting of offset and gain corrections for 32 outputs in six voltage ranges is compiled and stored in RAM.

These calibration coefficients are recalled each time the outputs are changed.

System Reset: After a system reset, all outputs are in offline mode, all control registers are in their default state, self-test is initiated, and auto-calibration is initiated.

Board Addresses: The VMEbus base address is set. There is one jumper for each address There is one jumper for each address A31 to A7;

The board occupies an address space of 128 consecutive bytes. The board occupies an address space of 128 contiguous bytes.

VMEbus Compliant: Address modifier bits are selected and decoded via jumpers to support unprivileged, supervisory, and non-privileged or supervisory board access.

Output Data Transfer: Output data is stored in 32 16-bit registers. The board is software configurable to accept binary or offset binary data.

Output changes can be initiated through register access, but the outputs are double-buffered, which allows all channels to be updated synchronously through software or external triggers.