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DA&C PCI cards

The RS-422/485 communication cards are also supplied besides the process-oriented PCI cards.

DA&C PCI cards - Analog Inputs

Type AIN ADC Buffer Isol. DAC CNT DIO
PCA-7208AL 8/32x S.E. 12-bit/ 10kHz 256B - - - - - - 2 8+8
PCA-7208AS 8/32x S.E. 12-bit/ 10kHz 256B - - - 2x12-bit 2 8+8
PCA-7228AL 8/32x S.E. 12-bit/ 100kHz 64kB - - - - - - 2 8+8
PCA-7228AS 8/32x S.E. 12-bit/ 100kHz 64kB - - - 2x12-bit 2 8+8
PCA-7228EL 8/32x S.E. 12-bit/ 80kHz 64kB 1 kV - - - 2 8+8
PCA-7408AL 8/32x S.E. 14-bit/ 10kHz 256B - - - - - - 2 8+8
PCA-7408AS 8/32x S.E. 14-bit/ 10kHz 256B - - - 2x12-bit 2 8+8
PCA-7428AL 8/32x S.E. 14-bit/ 100kHz 64kB - - - - - - 2 8+8
PCA-7428AS 8/32x S.E. 14-bit/ 100kHz 64kB - - - 2x12-bit 2 8+8
PCA-7428EL 8/32x S.E. 14-bit/ 80kHz 64kB 1 kV - - - 2 8+8

Several hints for the PCI card selection

  1. A decisive factor for achieving stable sampling at high sampling frequencies is the size of the data buffer. For example the value 256B provides the record of up to 128 samples, that means the 12.8ms measuring time at the measuring frequency of 10.000 samples/s. Because the optimal program service routine uses a block transfer at the 50% full buffer, the necessary application reaction time is up to 6 ms. In Windows this is usually matched with the included system driver, but during a higher system load by parallel processes it cannot be guaranteed.
    The sampling frequency is limited to 1 kHz when using the TEDIA_DAQ01 driver.
    The cards with the 64kB buffer then provide enough capacity even in the most severe conditions.
  2. The TEDIA cards are fitted with the "dual-port RAM" buffer, allowing the simultaneous access to the application and to the A/D converter circuits. The advantage compared to ordinary FIFO memories is a possibility of transfer of a selected data only, not all of them.
    For example let's mention an application, monitoring and transferring of one selected channel. Data of all other channels are not useful, so they are not even read.
  3. The essential feature (especially for on-line data processing) is a possibility of setting the buffer-full threshold detection operationally for the interrupt call.
    The cards fitted with standard FIFO allow the user to call the interrupt routine at the 50% full buffer (which is convenient for higher sample frequencies) or at the one sample present in the buffer at least (which is convenient for lower sample frequencies only).
    The PCA-7228A/7428A series cards enable the interrupt call optionally after every input sequence (i.e. the input set defined in the scanning logic) or every time the buffer is filled at the 256B, 512B, 2kB, 8kB or 32kB level.
  4. The scanning logic (i.e. circuits for selecting and defining the measuring input sequence) is an obvious part of every modern measuring card.
    However, some cards allow the user choosing a continuous input interval only (e.g. 1-5, 2-11), not random sets (e.g. 1, 3 and 7). Also the sequence timing is often derived from the trigger pulse generator at cheaper cards and the channels are measured out with the desynchronization then, depending on the sampling frequency (e.g. two inputs at 1kHz sampling frequency are sampled with the 0.5 ms pitch).
    The PCA-7228/7428 series cards allow the user to define up to 32 channels, as a random combination of inputs and voltage ranges (inputs may be repeated) including a definition of the time interval. In the event of two inputs mentioned above (sampled with 1kHz sampling frequency), these are sampled only with 10µs pitch!
  5. In some applications, the user needs to record (besides analog signals) also a state of the digital signals or the digital signals processed by the counter. All multifunctional cards mentioned above allow the user (if they have a counter) to record actual counter values into the data buffer, together with the analog values.
    In the event of recording logic signals, the cards allow the user to record four digital signals synchronously.

Other types of PCI cards

Type Description
PCD-7004 PCI card with digital ports (32 bi-directional lines, TTL levels)
PCD-7104 PCI card with digital ports (8 isolated inputs, 8 relay outputs)
PCT-7303A 3-axis quadrature encoder & counter PCI card
(3x 24-bit encoder/counter, 8+8 DIO)
PCT-7408A PCI card with recording counters
(8x 24-bit counter, 8x 32-bit timer, 8 relay outputs)
PCT-7424 PCI card with recording counters
(24x 32-bit counter, 8+16 DIO)