L-791 Multifunctional ADC/DAC board with galvanic isolation and BusMaster mode

Multifunctional ADC/DAC board with galvanic isolation and BusMaster mode
  • ADC: 14 bits / 400 kHz
  • Input channels: 16 differential or 32 with "common ground"
  • Galvanic isolation up to 500 V
  • DMA Bus Master mode at PCI
  • Digital inputs/outputs: 16/16
  • PCI 5.0V Card (5.0V Add-in Card)
  • Two-channel DAC (optional)

Universal PCI board with direct access to computer memory (DMA Bus Master), which saves CPU time of the computer and creates opportunities for working in real time. The unprocessed structure of the board greatly simplifies its programming.

The interface to the PCI bus and all the internal logic of the board are implemented with FPGA. Real frequency difference of interrogation of individual channels. Index 32-bit data sample format provides an explicit data binding to the physical channel number. Synchronous digital data input.

Group galvanic isolation of all external inputs and outputs from the computer, implemented on a modern element base, allows continuous transmission of data via galvanic isolation without losses at the maximum frequency of ADC and DAC operation.

Number of channels 16 differential or 32 with "common ground"
Resolution 14 bits
Effective resolution 
(input signal - 10 kHz sine / 4,9V)
13,3 bits (conversion frequency is 300 kHz)
Input impedance (at single-channel mode) Not less than 1 MOhm
Input signal measuring sub-ranges ±10 V, ±5 В, ±2,5 V, ±1,25 V, 
±0,6 V, ±0,3 V, ±0,15 V, ±0,07 V
Sample rates Up to 400 kHz
  • Internal
  • By external synchro-signal
Group galvanic isolation 500 V
Inputs protection ± 25 V (power on)
± 10 V (power off)
Inter-channel interference -70 dB (input signal - 10 kHz sine with output source impedance less than 1 kOhm)
The signal / (noise + nonlinear distortion) ratio
at a frequency of 400 Hz
74 dB
DAC (option)
Number of voltage outputs with common ground 2
Resolution 12 bits
Setting time 8 μs
Output range ±5 V
Output current, no more than 2 mA
DAC type Synchronous
Digital inputs and outputs
Number of inputs 16 (parallel, synchronous, asynchronous)
Number of outputs 16 parallel, asynchronous with common resolution outputs
Type of logic CMOS (74 НСТ), TTL-compatible
Dimensions       167x120 mm
  • L-791
    L-791 board, no DAC
  • OP-791D
    DAC installation


  • l791_users_guide.pdf (filesize: 1 355 222 bytes, date: 13.03.2013)

    User's Guide and low-level description of L-791 PCI board (Version 1.30). Adobe Acrobat 6.0.

LGraph2 software package

  • lgraph2.zip (filesize: 26 786 707 bytes, date: 11.10.2021)

    LGraph2 is a free multi-channel data recorder for Windows. Version 2.35.20 provides the possibility of simultaneous data visualization and recording from the ADCs: L-502, L-780M, L-783, L-791, E-502, E14-140, E14-140M, E14-440, E-154, E20-10, LTR11, LTR114, LTR27, LTR212, LTR216, LTR22, LTR24, LTR25, LTR51. It requires an updated version of the LComp driver (from version 01.04.2010) and ltrserver (no lower than

Software for Windows

  • lcomp.exe (filesize: 6 342 216 bytes, date: 12.05.2021)

    Beta version. LCOMP library for Windows XP/Vista/Win7/Win8/Win10 32 and 64-bit versions with drivers. The installer and drivers are digitally signed. The library is built on the basis of modern WDM-drivers rewritten on WDF. It includes the WDM driver itself for L-CARD hardware, the DLL library with source code, programming examples, electronic description, etc. The LCOMP library provides support for almost the entire range of products: PCI boards, USB modules. ISA support is excluded.

    The library includes “L-Graph I” software. L-Graph I supports the following devices: L-1450, L-761, L-780, L-783, L-791, E14-140, E-154 and E14-440. Files recorded by L-Graph I can also be read and processed using the demo-version of PowerGraph v.3.X.


Phone: +7 (495) 785-95-19
Fax: +7 (495) 785-95-14

Sales department: en@lcard.ru
Technical support: en@lcard.ru

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Moscow 117105
Russian Federation

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More than 3,000 customers worldwide are already using L-CARD electronic equipment for a wide range of research and industrial applications. We are glad to help you at any stage of creating an electronic product: from development and production to post-warranty support.



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