T7 eRead Command Triggers Disabled State

[bhathawayML]

I am communicating with a T7 LabJack device. I want to simply read the state of a pin, but while doing so this triggers the state of said pin. In the example below, I set pin MIO0 to True (validated with a vacuum line), then read the state using ljm.eReadName (same behavior with ljm.eReadAddress). This returns TRUE, however I can hear the vacuum line being disabled. When I call this same function again, it returns False and the vacuum remains disabled.

I hope I am not missing something obvious here. Any help/advice is much appreciated!

Versions: PyCharm 2023.3.7, Python 3.10, labjack-ljm 1.23.0

from labjack import ljm

device_sn = "470031969"
pin_name = "MIO0"

# Open device
try:
    device = ljm.openS("ANY", "ANY", device_sn)
except ljm.ljm.LJMError:
    raise Exception("No device detected!")

# Set pin status
ljm.eWriteName(device, pin_name, True)

# Get pin status
state = ljm.eReadName(device, pin_name)
print(bool(state))  # True

# Get pin status again
state = ljm.eReadName(device, pin_name)
print(bool(state))   # False

# Close device
ljm.close(device)

[ljrob]

Hello, The registers which interact with a single IO will automatically set the direction. So reading from "FIO3", "DIO3", EIO3, "DIO11" etc. will set the corresponding IO to input. When writing, it will set the IO to output. In your program. During the first read, the IO gets set to input. It reads high because the line needs some time to transition to low. When the second read occurs, the line has transitioned low and reads as such. You can use DIO_STATE to get the states of the lines without affecting direction. Another option is to only read from input lines and only write to output lines. For full details see the DIO section of the docs: https://support.labjack.com/docs/13-0-digital-i-o-t-series-datasheet Kind regards, Steve LabJack Support ***@***.*** LabJack Corporation 6900 W JEFFERSON AVE STE 110 LAKEWOOD CO 80235-2335 V:(303)942-0228 How did we do? Great / Okay / Not Good <https://docs.google.com/forms/d/e/1FAIpQLSfkvhb7q6YtG-fovIkV9xUABP6f4kfsZQpTetmHzw-yHLu3cA/viewform>

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On Wed, Dec 18, 2024 at 3:51 PM Brooke ***@***.***> wrote: I am communicating with a T7 LabJack device. I want to simply read the state of a pin, but while doing so this triggers the state of said pin. In the example below, I set pin MIO0 to True (validated with a vacuum line), then read the state using ljm.eReadName (same behavior with ljm.eReadAddress). This returns TRUE, however I can hear the vacuum line being disabled. When I call this same function again, it returns False and the vacuum remains disabled. I hope I am not missing something obvious here. Any help/advice is much appreciated! *Versions: PyCharm 2023.3.7, Python 3.10, labjack-ljm 1.23.0* from labjack import ljm device_sn = "470031969" pin_name = "MIO0" # Open device try: device = ljm.openS("ANY", "ANY", device_sn) except ljm.ljm.LJMError: raise Exception("No device detected!") # Set pin status ljm.eWriteName(device, pin_name, True) # Get pin status state = ljm.eReadName(device, pin_name) print(bool(state)) # True # Get pin status again state = ljm.eReadName(device, pin_name) print(bool(state)) # False # Close device ljm.close(device) — Reply to this email directly, view it on GitHub <#24>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACHTFXXUQPRW733ZFOBP5AD2GH4ATAVCNFSM6AAAAABT3WSZPSVHI2DSMVQWIX3LMV43ASLTON2WKOZSG42DQOBZGM4TSNA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>