Realtime datalog test from Raspberry Pi. Measure 10V from MM with good 3458A (-8.9ppm offset)
Download CSV file for full datalog details
Workflow:
* RPI accesses DMMs via GPIB and reads data.* Data is formatted by python script into DSV string and written/append to file on FTP
* DSV-file is visible publicly on https://xdevs.com/datashort/10v_3458_nplc200_mm.csv
* Page http://xdevs.com/datalog_mm/ runs D3.js javascript library to read DSV file test.log to input data
* D3.js plots SVG graph online :)
# # xDevs.com Python 10V test for 3458A # https://xdevs.com/guide/ni_gpib_rpi/ # https://xdevs.com/article/hp3458a_gpib/ # https://xdevs.com/fix/hp3458a/ import sys import Gpib import time import ftplib port = 21 ip = "ftp.xdevs.com" password = "datashort" user = "datashort" inst = Gpib.Gpib(0,3, timeout=60) # 3458A GPIB Address = 3 inst.clear() #Setup HP 3458A #inst.write("*CLR") inst.write("PRESET NORM") inst.write("OFORMAT ASCII") inst.write("DCV 10") inst.write("TARM HOLD") inst.write("TRIG AUTO") inst.write("NPLC 200") inst.write("AZERO ON") inst.write("LFILTER ON") inst.write("NRDGS 1,AUTO") inst.write("MEM OFF") inst.write("END ALWAYS") inst.write("NDIG 9") cnt = 0 tread = 2 temp = 38.5 inst.write("TEMP?") temp = float(inst.read()) reflevel = 10.0000000 ppm = 0 with open('10v_3458_nplc200_mm.csv', 'a') as o: o.write("date;hp3458a;level;temp;ppm_level;\r\n") o.close() ftp = ftplib.FTP(ip) ftp.login(user,password) # connect to xDevs FTP while cnt <= 10000000: cnt+=1 with open('10v_3458_nplc200_mm.csv', 'a') as o: tread = tread - 1 if (tread == 0): tread = 20 inst.write("TARM SGL,1") inst.write("TEMP?") temp = inst.read() print ("Uploaded to FTP\r\n") file = open('10v_3458_nplc200_mm.csv','rb') ftp.storbinary('STOR 10v_3458_nplc200_mm.csv', file) #upload file file.close() inst.write("TARM SGL,1") data = inst.read() ppm = ((float(data) / reflevel)-1)*1E6 inst.write("DISP OFF, \"%3.3f ppm\"" % float(ppm)) time.sleep(1) print time.strftime("%d/%m/%Y-%H:%M:%S;") + ("[%8d]: %2.8f , dev %4.4f ppm, T:%3.1f" % (cnt, float(data),float(ppm),float(temp) ) ) o.write (time.strftime("%d/%m/%Y-%H:%M:%S;") + ("%16.8f;%16.8f;%3.1f;%4.3f;\r\n" % (float(data),float(reflevel),float(temp),float(ppm) ) )) o.close()