#!/usr/bin/env python
import epics
from epics import caput
import numpy as np

# config
#STAGEpv = epics.PV('SLAAR11-LMOT-M452:MOTOR_1.VAL') # global globi
stagePV = epics.PV('SLAAR11-LMOT-M424:MOT.VAL')

c = 299792458

def mm2fs(d):
    # d in mm, output in fs
    return np.around(2*d*10**(-3)/c*10**15, decimals=5)

def fs2mm(t):
    # t in fs, output in mm
    return np.around(c*t/2*10**(-12), decimals=5)

t0 = 168.760 

while True:
    stagePV.put(t0 - fs2mm(200))
    stagePV.put(t0 + fs2mm(500))