This is the hardware manual (version V6.01) for the USB2813A, a USB-based data acquisition card from Beijing Aertai Technology. The card connects to a computer's USB port and is described as building data acquisition, waveform analysis and processing systems, as well as industrial field control systems; the listed uses are product quality testing, signal acquisition, process control and servo control.
The manual introduces the AD analog input section based on the ADS774JP converter with the INA128P amplifier, the DAC7625-based analog output section, TTL-compatible digital input and output registers, and an 8254 timer/counter. It then covers the component layout, the 37-pin analog connector and 34-pin digital connector pin definitions, jumper and potentiometer settings, signal connection methods, data formats and conversion formulas, a frequency-measurement example with the counters, and notes on use, calibration and warranty. This manual is written in Chinese.
| AD converter | ADS774JP |
|---|---|
| AD input range | ±10 V, ±5 V, 0–10 V |
| AD resolution | 12 bit |
| Maximum sampling rate | 100 kHz (per-channel rate = maximum rate / number of channels scanned) |
| Physical AD channels | 16 single-ended (SE), 8 differential (DD) |
| Instrumentation amplifier | INA128P, gain G = 1 + 50 kΩ / R1 |
| Analog input impedance | >100 MΩ |
| DA converter | DAC7625 |
| DA output range | 0–5 V, 0–10 V, ±5 V, ±10 V |
| DA output channels | 4 |
| DA output rate | 100 kHz (10 µs/point), settling time 10 µs |
| Digital input register | 74LS245, TTL compatible |
| Digital output register | 74ALS273, TTL compatible |
| Timer/counter | 8254, three independent 16-bit down counters |
| On-board clock output | 2 MHz, 0.5 µs period |
The AD inputs can be set to ±10 V, ±5 V or 0–10 V, with 12-bit conversion accuracy.
It has 4 analog output channels and an output rate of 100 kHz (10 µs per point).
The maximum total sampling rate is 100 kHz; the rate of each channel equals the maximum rate divided by the number of channels being scanned.
It provides three independent 16-bit down counters, with four operating types, six count modes and binary or BCD counting selectable in software.