add measurement and script for directly connected full load test

data/ea_control_direct.py

@@ -0,0 +1,101 @@
+from labcontrol.ea import EA_PS8080
+from labcontrol.ea import EA_EL9080
+from labcontrol.ea import EA_interface
+import time
+
+# Setup
+maxpower    = 2000
+psvolt      = 48.0
+steps       = 40
+settletime  = 10
+measures    = 4
+measuretime = .5
+
+# defines
+stepwidth = maxpower/psvolt/steps
+starttime = time.time()
+
+def identify(devlist):
+    outdict = {}
+    for dev in devlist:
+        devid = EA_interface(dev).write(12, 0, [])
+        if "PS" in devid[1]:
+            devtype = "ps"
+        else:
+            devtype = "el"
+
+        outdict[devtype] = {"id":devid[1][:-1], "address":dev, "type":devtype}
+
+    return outdict
+
+def init(tree):
+    for dev, dat in tree.iteritems():
+        if dat['type'] == "el":
+            devobj = EA_EL9080(tree[dev]['address'])
+        else:
+            devobj = EA_PS8080(tree[dev]['address'])
+        
+        #devobj.interface.debug_output = False
+        devobj.remote(True)
+        time.sleep(1)
+        
+        if dat['type'] == "el":
+            devobj.set_current(0)
+            devobj.enable(True)
+        else:
+            devobj.set_current(maxpower/psvolt)
+            devobj.set_voltage(48)
+            devobj.output(True)
+        
+        tree[dev]['dev'] = devobj
+
+def deinit(tree):
+    for dev, dat in tree.iteritems():
+        if tree[dev]['type'] == "el":
+            tree[dev]['dev'].enable(False)
+        else:
+            tree[dev]['dev'].output(False)
+        tree[dev]['dev'].remote(False)
+        tree[dev]['dev'].close()
+
+def measurement(devicetree):
+    print("starting Measurement (approx {}s)".format(steps*(settletime + measures*measuretime)))
+    log = "time,set_curr,set_volt,act_curr_ps,act_curr_el\n"
+    devicetree['ps']['dev'].set_current(stepwidth*steps)
+    for i in range(1, steps):
+        steppos = i*stepwidth
+        try:
+            devicetree['el']['dev'].set_current(steppos)
+            time.sleep(settletime)
+            act_el = 0
+            act_ps = 0
+            for m in range(0, measures):
+                act_el += devicetree['el']['dev'].get_actual_values()['i']
+                act_ps += devicetree['ps']['dev'].get_actual_values()['i']
+                time.sleep(measuretime)
+
+            act_ps = act_ps/measures
+            act_el = act_el/measures
+            log_new= "{:.3f},{:.3f},{:.1f},{:.3f},{:.3f}\n".format(
+                time.time()-starttime, 
+                steppos,
+                48.0, 
+                act_ps,
+                act_el                
+            )
+            log += log_new
+        except Exception as e:
+            print type(e)
+            print e
+
+    print(log)
+    with open('./log.csv', 'w') as f:
+        f.write(log)
+
+if __name__ == "__main__":
+    devicetree = identify(["/dev/ttyUSB0","/dev/ttyUSB1"])
+    print(devicetree)
+    init(devicetree)
+    init(devicetree)
+    measurement(devicetree)
+    deinit(devicetree)

data/log_2kw_direct.csv

@@ -0,0 +1,40 @@
+time,set_curr,set_volt,act_curr_ps,act_curr_el
+16.357,1.042,48.0,0.870,1.047
+28.546,2.083,48.0,1.839,2.031
+40.752,3.125,48.0,2.835,3.031
+52.939,4.167,48.0,3.939,4.141
+65.100,5.208,48.0,4.965,5.172
+77.241,6.250,48.0,6.054,6.250
+89.367,7.292,48.0,7.062,7.258
+101.493,8.333,48.0,8.149,8.352
+113.651,9.375,48.0,9.159,9.359
+125.777,10.417,48.0,10.262,10.461
+137.903,11.458,48.0,11.272,11.477
+150.061,12.500,48.0,12.248,12.453
+162.235,13.542,48.0,13.335,13.531
+174.425,14.583,48.0,14.325,14.531
+186.615,15.625,48.0,15.408,15.609
+198.805,16.667,48.0,16.385,16.625
+210.979,17.708,48.0,17.470,17.703
+223.169,18.750,48.0,18.464,18.672
+235.342,19.792,48.0,19.433,19.656
+247.532,20.833,48.0,20.515,20.734
+259.738,21.875,48.0,21.505,21.734
+271.944,22.917,48.0,22.586,22.820
+284.150,23.958,48.0,23.561,23.797
+296.355,25.000,48.0,24.697,24.938
+308.546,26.042,48.0,25.685,25.906
+320.736,27.083,48.0,26.790,27.016
+332.925,28.125,48.0,27.771,28.000
+345.115,29.167,48.0,28.752,28.977
+357.289,30.208,48.0,29.832,30.078
+369.479,31.250,48.0,30.844,31.078
+381.670,32.292,48.0,31.934,32.156
+393.859,33.333,48.0,32.917,33.164
+406.049,34.375,48.0,34.020,34.250
+418.223,35.417,48.0,35.041,35.281
+430.413,36.458,48.0,36.191,36.422
+442.602,37.500,48.0,37.209,37.438
+454.793,38.542,48.0,38.183,38.422
+466.983,39.583,48.0,39.244,39.492
+479.172,40.625,48.0,40.246,40.500

data/processing.py

@@ -1,16 +1,44 @@
 #! /usr/bin/python3
 
+import numpy as np
 import pandas as pd
 import matplotlib.pyplot as plt
 plt.style.use('bmh')
 
-data = pd.read_csv("log.csv")
+data = pd.read_csv("./log_2kw_direct.csv")
 
 print(data)
 
-plt.errorbar(data['time'],data['act_curr_ps'], yerr=data['act_curr_ps']*.002, fmt='.')
-plt.errorbar(data['time'],data['act_curr_el'], yerr=.125, fmt='.')
-plt.bar(data['time'], data['act_curr_el']-data['act_curr_ps'], 2, aa=True)
-plt.ylabel('I/A')
-plt.xlabel('t/s')
+#plt.errorbar(
+#    data['time'],
+#    data['act_curr_ps'], 
+#    yerr=data['act_curr_ps']*.002, 
+#    label="Spannungsquelle Ausgang",
+#    fmt='.'
+#)
+#plt.errorbar(
+#    data['time'],
+#    data['act_curr_el']-.125, 
+#    label="Elektronische Last Eingang",
+#    fmt='.'
+#)
+data['act_curr_el'] = data['act_curr_el']-.125
+meandist = np.mean(data['act_curr_el'] - data['act_curr_ps'])
+plt.bar(data['set_curr'], (data['act_curr_el']-data['act_curr_ps']-meandist), .2, aa=True)
+
+data['nom_max_delta_i'] = np.sqrt(2*(data['set_curr']*.002)**2)
+plt.errorbar(
+    data['set_curr'],
+    data['nom_max_delta_i'],
+    fmt='.'
+)
+plt.errorbar(
+    data['set_curr'],
+    -data['nom_max_delta_i'],
+    fmt='.'
+)
+
+plt.ylabel('$\Delta$I/A')
+plt.xlabel('I$_{set}$/A')
+plt.legend()
 plt.show()