I was wondering if someone could help me here with the problem i have running 2 VM140 boards in Python.
I am trying to run two Python scripts each one getting data from one VM 140 board. When i start the first script
it opens the card and i get data, but when i start the second script, it is not able to open the second card. When
i stop the first script the second script is able to open the card and works ok.
I have set the jumper id’s on both cards. One to id0 and the other to id1.
Both card are working in the demo.exe program that is supplied with boards.
I am kinda confused how i should open the cards in the scripts. Should i open both cards in one script, or
is it possible to open the seperate cards in each script. ??
What I was trying to tell is that to debug a script, we kind of need to see the script, not just a description of what it does
Opening the same device in two separate applications at the same time, is not possible. Opening device A in application A, and opening device B in application B, is possible.
I want to do the second thing you mentioned: Opening device a in application a, and opening device b in application b.
Here is part of the python code that runs without problems on card 0. How do i use this code (applied to card 1) to open the second card and
read that card.
Thank you for your time !
from ctypes import *
from time import *
global CardAddress
CardAddress = 0
def startupcard ():
import time
print ""
print "Initial Startup ......"
print ""
time.sleep( 1 )
connectioncheck()
powergood()
windll.k8061.ClearAllDigital(CardAddress)
windll.k8061.ClearAllAnalog(CardAddress)
time.sleep( 1 )
return
def connectioncheck ():
import time
windll.k8061.OpenDevice()
if windll.k8061.Connected(CardAddress):
print "Connection Card is OK !"
print ""
else:
print "Connection Card is NOT OK !"
print ""
print "Retrying ..."
print ""
time.sleep( 5 )
connectioncheck()
time.sleep( 1 )
return
def powergood ():
import time
if windll.k8061.PowerGood(CardAddress):
print "Power Supply is OK !"
print ""
else:
print "Power Supply is NOT OK !"
print ""
print "Retrying ..."
print ""
time.sleep( 5 )
powergood()
time.sleep( 1 )
return
def getvalues ():
windll.k8061.OutputAnalogChannel(CardAddress,1,129) #Setting analog out to supply 5V analog in.
global anin1, anin2, anin3, vanin1, vanin2, vanin3
anin1 = float(windll.k8061.ReadAnalogChannel(CardAddress,1))
anin2 = float(windll.k8061.ReadAnalogChannel(CardAddress,2))
anin3 = float(windll.k8061.ReadAnalogChannel(CardAddress,3))
return
def printvariables ():
import time
from datetime import date
global date
date = date.today()
print ""
print "Analog input channel 1 =", anin1,"dec" " Timestamp : %s" % time.ctime()
print "Analog input channel 2 = ", anin2,"dec" " Timestamp : %s" % time.ctime()
print "Analog input channel 3 =", anin3,"dec" " Timestamp : %s" % time.ctime()
print ""
startupcard()
getvalues()
printvariables()
Well i tried some things but that is not the case.
When i do a “windll.k8061.OpenDevice()” and
after that i do "windll.k8061.Connected(0) it will return a 1.
When i check card 1 with “windll.k8061.Connected(1)” it returns a 0.
So this one is not opened yet.
When i again do “windll.k8061.OpenDevice()” both cards give a 1
when i check with the connected() command.
I am also able to close the cards one by one using the closedevice() command.
Is there not some way to split up the dll reading completely. I am using the script to do longtime logging, and cards have to beconnected one after another and stopping the script for adding another card is no option.
You can use the return value of the OpenDevice as the card address.
Use this value in the next function calls to access this card.
When more than one K8061 card is connected to the PC, repeat the OpenDevice function call until all the cards are opened.
Well of course i have read the dll manual you’re referring to.
From your answers i am making up that Velleman also does not exactly know the answer
as i dont get a direct answer.
I have tried al things last night and my conclusion is that once you have opened one card
in script x it is impossible to open the other card in script y. Executing the opendevice command
results in a -1 value that means al cards are openened.
I will rewrite the program for another another card as the VM140 is useless this way.
