Regarding the status of the USB-2537's DIO port

[Fukuda]

Hello,

I would like to know the status of the USB-2537 DIO port under the following conditions (INPUT/OUTPUT, High/Low/HighImpedance, etc.).

#1. Signal status of each DIO A,B and C ports with only external power turned on

#2. From the above state, the signal state of each DIO A,B and C ports with voltage applied to the USB port

#3. Signal status of each DIO A,B and C ports when the OS starts from the above state and is not recognized as DAQ

#4. Signal status of each DIO A,B and C ports after PC recognized as DAQ.

#5. Signal status of each DIO A,B and C ports when the OS is shut down from the above state

On the actual unit, #3 and #4 show different states, #3 is low and #4 is high, is this by design? Also, are the statuses of #1, #2, and #5 correct as they are indefinite?

Thanks,

[DAQman]

When power is applied to the board, nothing happens until the USB is connected. When this occurs, the driver starts up and systematically turns on power to board sections to minimize inrush current. At this time, the digital IO is configured as inputs all high. The board is not powered on if the system fails to recognize it. If the computer is shut down or the USB cable is removed, the port state should drop to zero volts because board power is removed. The board must be in contact with the device driver for it to remain powered. There may be a case where the USB driver crashes and leaves the board power applied, but I cannot verify this.