<html><body><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div><div>Regarding a conversion effect or rounding effect, we are converting the excitation currents written to the LV Chassis to hexadecimal. Using a separate hexadecimal conversion test VI, there is a situation where if 1.0 uA < I1 < 1.5 uA and 0.5 uA < I2 < 0.75 uA (since I2 = I1 / 2), it is causing the hexadecimal conversions of I1 and I2 to be the same. </div><div><br data-mce-bogus="1"></div><div>However, I am not sure if I1 is in that range when the hang-up at 325K occurs. This can be checked next to time the error occurs.</div><div><br data-mce-bogus="1"></div><div>I am also not sure if this is something that could just be fixed by changing a setting in how LabVIEW converts the decimal value to hexadecimal.<br data-mce-bogus="1"></div><div><br></div><div>Tyler<br data-mce-bogus="1"></div></div><div><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>From: </b>"Brian Eng" <beng@jlab.org><br><b>To: </b>"Amrit Yegneswaran" <yeg@jlab.org><br><b>Cc: </b>"dsg-hallb magnets" <dsg-hallb_magnets@jlab.org>, "dsg-internal" <dsg-internal@jlab.org><br><b>Sent: </b>Thursday, February 9, 2017 1:18:49 PM<br><b>Subject: </b>Re: [Dsg-internal] [Dsg-hallb_magnets] cernox sensors.<br></div><br><div data-marker="__QUOTED_TEXT__">> On Feb 9, 2017, at 12:57 PM, Amrit Yegneswaran <yeg@jlab.org> wrote:<br>> <br>> thanks for the info brian.<br>> glad to know you are back.<br>> <br>> since it is algorithmic on the spare excitation chassis, one could infer that the spare excitation chassis is in the clear.<br>> for the one in use, one can't make this inference, i guess because you haven't tested it.<br><br>It isn't a true spare, more like a prototype. Plus we usually only simulate a few channels at a time with it, not even a fully loaded one like in the Hall. There's also the fact that there's six chassis to read from, which also could be a factor in the bad readings.<br><br>> one other question: since you say the resistance goes down to 0 ohms, V1 must be very very close to V2.<br>> so when the difference is taken, could there be any precision/ bit resolution/ rounding effects in play.<br>> i'm sure you have looked at this possibility.<br><br>Not just close but both voltage readings are the exact same when it gets stuck at 325.<br><br>So that's what would be used to determine if the initialization should be performed again, if they were merely just close that would be a valid reading.<br><br>_______________________________________________<br>Dsg-internal mailing list<br>Dsg-internal@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/dsg-internal<br></div></div></body></html>