OPCARD -01/100 is a complete ultrasonic testing device, suitable for all ultrasonic measurements, and due to many additional digital inputs/outputs and internal processor it can be used as a controller for more complicated devices.

The card can work together with following devices:

· 32 channel multiplexer - the card can control it directly;
· Scanner - it has input for incremental encoders;

The card has an implemented one channel pulser & receiver and can be used with one transducer or with two (one is sending and the second receiving).

OPCARD -01/100 is a short PCI card and can be installed in a standard PC.

Technical data

A/D converter:
- Resolution: 8 bit
- Sampling frequency: 12.5,25,50 or 100MHz1
Data buffor 256, 512, 1K, 2K,4K,8K,16K, 32k, 64k, 128k1
Analog parameters:
- Input amplifier gain: from -20dB to 76dB1
- Input attenuator: off or -20dB1
- Sensitivity: 0.1mV - 1Vpp
- Bandwidth: 0.5 MHz - 25 MHz (-3dB)
- Input impedance 50 Ohm, 10pF
- Filters switchable 0.5 - 6MHz1, 0.5 - 10MHz1, 0.5 - 15MHz1, 0.5 - 25MHz1,
1 - 6MHz1, 1 - 10MHz1, 1 - 15MHz1, 1 - 25MHz1,
2 - 6MHz1, 2 - 10MHz1, 2 - 15MHz1, 2 - 25MHz1,
4 - 6MHz1, 4 - 10MHz1, 4 - 15MHz1, 4 - 25MHz1
Pulser:
- Pulse Voltage off(0V) to 360V (positive pulse, Short circuit step pulser)
- Fall Time <= 20 ns
- Pulse Duration Short circuit, bandwidth up to about 50MHz
- Output impedance < 1 Ohm
Delay time: Post trigger 256us, measurement accuracy better than 1ns
Data buffer: 256, 512, 1K, 2K,4K,8K,16K, 32k, 64k, 128k1
DAC (TGC) with arbitrary waveform generator
- Frequency 50MHz
- Resolution 8 bit
- Max. Gain changing 48dB pro step
Counters / Input for incremental encoder:
- Counters for Incremental Encoders 2 channel 16-bit
Trigger
- Internal trigger rate Software
- External trigger rate TTL Signal
- Multiplexer control Software
- Trigger output signal TTL Signal
Additional inputs:
- 2 x digital line TTL Signal
Output:
- 5 x digital line TTL Signal
Data bus: PCI (short card)
Transfer: Bus Mastering DMA data transfer

Signals on the external connectors

Lemo:
PE - Measured input signal (sending / receiving);
TT - Measured input signal (receiving);

DB15:
Pin1, 9 - TTL encoder input signals
Pin2, 10 - TTL general input signals
Pin4 - TTL trigger out signal
Pin5, 6, 7, 12, 13 - multiplexer channels control lines
Pin8 - +12V
Pin15 - -12V
Pin14 - GND

Characteristic of the card:

One of the most important features of the card is a precise synchronization between the transmitter trigger signal postTrigger and the moment when the sampling of the input signal starts.
This time (postTrigger) is software programmable in the range of 0 – 255us with a resolution of 1us and has stability within the range of 1ns. It is particularly important in the case of scanning devices, since it allows to achieve a very small time skew between different positions (channels). 1ns would correspond to a clock frequency of 1GHz which is much higher than the actual frequency used.

Characteristic of the pulser on board:

Pulser circuit waveforms: The rising edge of the Trigger signal (described as Trigger) initiates the transducer charging process which takes about 3us. After this time a transistor switch which discharges the transducer is turned on (discharge time is about 20ns, but it can be longer, if the capacitance of the transducer is too large; the limit is reached, if the transducer is made from the standard ceramics, is 0.1 mm thick and has 8 mm diameter).

ecause of the very low output impedance of the device (<1 Ohm) and short discharge time the pulse generated with this device could be concerned as a real pulse answer for the most transducers. Transducers with a parallel matching inductance should not be used, since they do not allow the transducer to be pre-charged (the inductance causes a short-circuit).

Software Package

The software (for Windows 95,98/NT 4.0/2000/XP) includes all necessary functions for ultrasonic measurements.


Technical description of the OPCARD