import numpy as np
import epics
from matplotlib import pyplot as plt


from epics import caget, caput, cainfo

threshold = 0.2

monitor_ch = 'SLAAT21-LMOT-M703:MOT'


current_ch = caget(monitor_ch)


c = 0
while c == 0:
    current_ch = caget(monitor_ch)

    print('value checked and it is : ' , current_ch)
    print('####### -----   #######')

    if np.abs(current_ch - 55.7 ) > threshold:

        plt.figure(figsize = (50,5))
        plt.plot((0,500),(0,1), lw = 0.001)
        plt.text(0.5, 0.5,'stage_moved', fontsize = 100, color = "r")
        plt.show()