Monday - Thursday:
6:30am - 5:00pm PST
Friday (no shipping):
6:30am - 4:00pm PST
|Relative Humidity (non-condensing)||0||95||%|
|Supply Voltage||8V to 25V|
|Digital Output Pins||Open drain voltage, 25V max.
Open drain sink current, 1A max.
|Digital Input Pins||VIL(max) = 0.8V
VIH(min) = 2.0V with approx. 100 mV of hysteresis
VIH(max) = 24V
|Analog Output Range||12-bit DAC, 0V to 5V|
|Analog Input Range||12-bit ADC, 0V to 5V|
|Power consumption||115 mA @ 8 V, 77 mA @ 12 V or 42 mA @ 24 V typical.
(USB 2.0 connection, no encoders connected, all LED's off)
|Max. current drawn from +5V outputs||550 mA (combined current of all +5 V output terminals on USB4)|
|Max. encoder input frequency||5 MHz|
|Max. FIFO write speed (Time Based Triggering)||500 kHz|
|Max. FIFO write speed (Event Based Triggering)||Counter - 200 kHz, Input Port - 100 kHz|
Encoder Channel 3,2,1,0 (J3, J4, J5, J6) Pin-out (USB4-S option):
Single Ended input circuit (internal to USB4):
Encoder Channel 3,2,1,0 (J3, J4, J5, J6) Pin-out (USB4-D option):
Differential Input Circuit (internal to USB4):
|1||+5V power out|
Input Port Circuit (internal to USB4):
|2||E-Stop input (active low)|
Output Port Circuit (internal to USB4):
Note: When driving inductive loads, add an external reversed biased diode in parallel with the load to protect the USB4 from damage caused by large voltage transients.
|4||DAC0 (analog outputs)|
|8||ADC0 (analog inputs)|
ADC Input Circuit (internal to USB4):
DAC Output Circuit:
The USB4 is a data acquisition device designed to record data from 4 incremental encoders, 8 digital inputs and 4 analog input channels. In addition, the USB4 provides 8 digital outputs and 4 analog output channels. The 8 digital outputs also have a latching emergency stop (E-Stop) input. When the E-Stop input is activated, the 8 digital outputs will turn off immediately. The analog input/output channels provide 12-bit data conversions at rates up to 44 kHz per channel.
All communication between the USB4 and the host PC is sent over a High-Speed USB 2.0 interface. The USB4 is compatible with USB 2.0 hubs, allowing multiple USB4 units to be used with a single PC. To handle continuous streaming of data over USB to the host PC, the USB4 has a 32 Mbyte FIFO to buffer the captured data when the host PC or USB bus is busy. Note that 32 Mbyte FIFO functionality is only available with a High-Speed USB 2.0 connection.
The digital input port can handle input logic levels from +3V to +25V and the digital output port has open drain MOSFET outputs to switch up to 1A at +25V. The range of the analog input/output channels is 0V to +5V. Four independent, flexible, incremental encoder interfaces are implemented in hardware on the USB4. Each encoder channel has a 24-bit up/down counter that is easily reconfgured for various counting modes such as modulo-N, non-recycle, range-limit and normal counter mode. Quadrature input modes of x1, x2, x4, clock/direction, and indexing modes can also be selected. Each encoder channel can also measure the pulse width and pulse period of its "A" input while simultaneously decoding the quadrature state. This feature allows RPM speed measurements to be made from the encoder input or interfacing to sensors with PWM (pulse width modulated) outputs.
The USB4 can capture data once per clock cycle of a user programmable 32-bit clock generator or on every rising or falling edge of the input port pins. Data capture can be programmed to run continuously or to start only when certain conditions are met such as the encoder count matching a certain value, or if the there is encoder movement in a certain direction. Encoder events can also output on the output port to trigger external devices. Trigger conditions can also be set for the analog input and PWM input channels; in addition, the USB4 can be configured to have the input port pins serve as a trigger to start data acquisition. The input port triggering is flexible and allows the user to form the final trigger from a combination of conditions on the input port with up to 2 levels of triggering. For example, trigger1 can be set to a rising edge of bit 0 and bit2, trigger2 can be set to a falling edge on bit3. Data capture will only start if trigger1 occurs first, then trigger2.
All the software and documentation needed to use the USB4 is available from US Digital. A PC demo application allows the user to confgure and explore various features of the USB4 using a graphical user interface. A library with a detailed Application Programming Interface is available so users can develop their own applications; additionally, US Digital provides several examples that demonstrate how to use the FIFO, how to log data, etc. For users that prefer lower level control, a documented register based interface is provided so the USB4's internal registers can be confgured at the bit level.