The following script shows how an input register senses the state of an output register.
#!/usr/bin/python3
import PyTango as tango
import matplotplib.pyplot as plt
try :
dev = DeviceProxy("pXX/lmscreen/LM_XX")
frame = dev.read_attribute("Value")
plt.imshow(frame)
plt.show()
except Exception as err:
print("Failed with exception: {}!".format(err)
print sys.exc_info()[0]