Miniball Autofill System User Guide 1 Logging in 2 Nomenclature
Contents
1. the box provides an interface with a high resistance in parallel to the PT100 This has little impact on the measured temperature but insures that if the PT100 is unplugged the neighbouring PT100 doesn t give spurious values For the PT100s the only thing to do is unplug the D sub connectors coming from the detectors from one PT100 box and plug them into the other one The manifold control on the old ISA based system consists of a 96 channel digital I O card inside pcepsc22 with two flat cables coming out which plug directly into the manifold controllers for manifolds B and D The connection from B to A and from D to C is made by two short flat cables The new system is the USB equivalent of this card and is pin to pin compatible so there are again two flat cables which connect in exactly the same way to the manifolds B and D Agian the connections from B to A and D to C is made by the two short flat cables Do not run both computers at the same time as the one which is not connected to the UPS will complain about this and they will interfere with each other when they try to update the website The procedure to switch from one system to the other is as follows e Shut down the computer which was working as filling computer and switch it off e Unplug the serial cable which connects that computer to the UPS and plug it into the computer which is to be the filling computer Unplug the grey flat cables which connect manifolds B and D to the2. 9 09 10 03 2003 C2 98 0 K Thu Jan 9 09 10 03 2003 C3 96 1 K Thu Jan 9 09 10 03 2003 4 2 show_last_fill This command should give an output like Date Time Out Program Outlet Fill Purge Fill let status status type time time Thu Jan 09 04 00 01 A1 SUCCESS DONE AUTOMATIC 110 252 Wed Jan 08 10 00 01 A2 SUCCESS DONE AUTOMATIC 92 254 Thu Jan 09 04 00 01 A3 SUCCESS DONE AUTOMATIC 110 251 Thu Jan 09 04 00 01 A4 SUCCESS DONE AUTOMATIC 110 237 Thu Jan 09 04 00 01 C1 SUCCESS DONE AUTOMATIC 78 196 Thu Jan 09 04 00 01 C2 SUCCESS DONE AUTOMATIC 78 186 Thu Jan 09 04 00 01 C3 SUCCESS DONE AUTOMATIC 78 180 In this example all of the outlets were filled at 4 AM on the 9t except for A2 which was taken out of the system deliberately in this case The fill types can be MANUAL AUTOMATIC or EMERGENCY depending whether the fill was issued by a user from the command line by the cron daemon automatically or by the PT100 indicating a detector was warm or warming up The purge times should be just over a minute unless the manifold was already cold in which case it will be shorter and the fill times should be under 5 minutes A negative value indicates that the purge or fill didn t even start This should be accompanied by an error message in the outlet status column The program status only indicates what happened to the program not the fill In other words it indicates SUCCESS if the program terminated cleanly even if it was unable to fill corr
3. filling computer and plug in the corresponding cables from the other computer in their place Unplug the PT100 connectors D sub which connect the detectors to the PT100 box and plug them into the other PT100 box e Unplug the ethernet switch hub from the second ethernet port of the computer which was being used and plug into the second ethernet port of the other computer e Make sure that the computer which is to be used as filling computer is plugged into the UPS for its power supply e Start this computer
4. same messages are sent to the system logger and end up in var log messages so you should look there if you need them In general they are only useful for debugging In order to change the crontab use the command crontab e This should start emacs on the crontab Just edit it as you desire but be careful not to get the syntax wrong and when you save and exit it will be installed 7 Emergency filling Emergency filling is completely independent of automatic filling It is controlled by the PT100 readout If a PT100 readout indicates a detector is either warm between 105 K and 200 K or if the temperature rises at more than 1 K per minute up to 130 K an emergency fill will be triggered on the corresponding outlet regardless of whether it is configured or not in the crontab for the automatic fill So always make sure that the appropriate LN2 line is connected for any detector which has a PT100 connected to the readout In theory if a PT100 is not connected that detector should never receive an emergency fill Unfortunately sometimes we seem to get glitches on the hardware which cause it go give false readings For this reason we have a file which lists the detectors which are disabled for emergency fill purposes they can still be filled manually or automatically To change the list of detectors for which emergency fills are disabled modify the file home miniball autofill emergency_fill_disabled sh It is a bash shell script which is
5. sourced and should look something like bin bash This is the list of detectors which are disabled for the purposes of emergency fills triggered by the PT100 readout This has no effect whatsoever on the fills invoked manually by the user or automatically from cron DISABLEDLIST A4 B1 B2 B3 B4 C4 Di D2 D3 D4 In this example only detectors A1 A2 A3 C1 C2 and C3 can be filled by the emergency fill Note that you can change this file from the GUI af_config by clicking on the red green buttons In that case red means emergency fills are disabled 8 Manual filling To issue a fill manually use the command fill followed by the list of outlets to fill The outlets have names like Al manifold A outlet 1 etc For example fill al a2 a3 cl c2 c3 9 Filling by hand If the software doesn t work at all try turning the key on the manifold control box below the filling computer to the manual position Then you can use the switches to open and close the valves First purge the manifold by opening the inlet and the purge valve until you see liquid nitrogen at the purge outlet Then close the purge valve and open the valves for the detectors you want to fill leaving the inlet open When each detector is full close its valve and when all are full close the inlet valve and return the key to the automatic position If even that doesn t work you can always use a funnel and pour it in 10 Disabling all fills T
6. Miniball Autofill System User Guide Author Nigel Warr Date 15 May 2008 gt Miniball filling status s for each outlet Out Program Outlet i Purge Fill status y time time DONE ANUA 180 DONE MANUAL DONE MANUAL DONE MANUAL DONE AUTOMATIC DONE AUTOMATIC DONE AUTOMATIC DONE AUTOMATIC M N J oO WWW oo N N wu as Oo PT100 readings for each outlet Enable disable emergency fills Outlet Cl r Temp estam AL 12 106 5 K gt Jun 23 200 m B1 aj D1 A2 22 SIIK ue Jun 200 Ad 2 C1 4 6 K Tue Tue Jun Tue Jun Tue Starting to purge manifold A of manifold A complete aft ed for manifold A outlet manifold A outlet 3 fully filled manifold A outlet 3 after 5 seconds Closing manifold A outlet 4 C manifold A inlet after 181 s fully filled manifold o 4 after 172 17 seconds ully completed fill on manifold A Figure 1 The GUI 1 Logging in There are now two autofill computers One is intended to be the backup of the other The new one is pcepuis36 cern ch and the old one is pcepuis20 cern ch when it is in CERN Only one should be running at any one time and it is only possible to connect one at a time to the hardware They should have the same configuration from the users point of view though the hardware is different The account and password are the same as on the DAQ computer If the machine has just booted it will not be in graphical mode so you have to type the command startx to switch t
7. be plugged into an ethernet hub or switch and the HV should be plugged into the same hub or switch There should be no uplink to the outside world it is supposed to be a private network it must be for CERN computer rules and if the HV system appears on the CERN network the CERN network people deliberately crash it Make sure that this switch or hub the HV mainframe and whichever computer is being used as a filling computer obtains its power from the UPS There are two PT100 boxes one for the old ISA based system and one for the new USB based system They are quite different The ISA system is a card inside pcepsc22 which has a connector that is connected by a flat cable to the PT100 box This card is an ADC and a few digital I O lines The I O lines are used to control a multiplexer inside the PT100 box which connects the selected channel to the ADC A current source also in the PT100 box is used to send a constant current through the PT100 and the ADC measures the voltage From that we calculate the resistance and from there the temperature The new PT100 system consists of two USB TEMP modules which are mounted inside the new PT100 box Each one is capable of reading 8 PT100s independently There is no connection between them inside the box and they have separate USB connections to pcepuis20 via a USB hub However as they give spurious readings when only one channel is connected and in any case we need the D sub connectors for compabibility
8. dout for a channel by setting the gain to something like 9 44 so that all values are out of range This is useful for channels that do not have a physical connection which can give spurious values 13 Troubleshooting If a fill command hangs and nothing happens check if there is another fill command running If so do a killall fill and try again If one fill program is still running for some reason even if it is not doing anything it keeps the semaphore locked so no other fill can start If you get a HARDWARE_ERROR status check all the connections to the manifolds and the manifold controller This error occurs when the computer tells the manifold controller to set the valves to a particular state and when it asks them what state they are in they are not in the desired state If LN2 flows out of a purge or detector outlet but the program doesn t react to that check that the LN2 detect light on the manifold controller box is reacting to the LN2 If it isn t you probably need to adjust the threshold using the screw near the light on the controller box They seem to drift with time so if you see that fill times are getting longer and longer check that it is detecting LN2 as soon as it is really flowing If you hear the click of the valve for a detector outlet open it vibrates a little when it is open too but no LN2 is flowing into the detector the line is probably blocked This can either be a kink of the line or ice in the lin
9. e In the former case straighten the line and in the later stop filling take the line out of the detector thaw it out let the water run out put it back and try again If the valves don t open and the LEDs on the manifold control box don t change when the program runs check the connection between the computer and the manifold control box If the LEDs change from red to green but the valves don t open check the connection from the manifold control box to the manifolds If the system fills but no e mail is sent check the syntax of the mailrc file in the autofill home directory Comments are not allowed and the mail program is a bit picky about the syntax If that is OK try sending mail from the system using the mail command by hand and see what happens If the temperature on a PT100 suddenly starts oscillating I have no idea what that is but it is a nuisance The only thing I can suggest is to add that outlet to the disabled list for emergency fills and keep a close eye on it because it won t have emergency filling to fall back on If a PT100 value suddenly appears in the list for a channel which has no PT100 connected I don t know what that is either Just make sure that outlet is in the disabled list If computer controlled filling doesn t work try turning the key to manual and operating the switches If you get a PURGE_TIMEOUT condition and no LN2 comes out of the purge outlet check there is LN2 in the vessel and
10. e that they are current because if the network is down this information is not updated 6 Automatic filling The automatic filling is performed using cron see the cron 8 man page and runs under the miniball account Log into that account and you can use the command crontab 1 see the crontab 1 man page to see the current configuration This should give something like the following The syntax is described in the crontab 5 man page MAILTO warr ikp uni koeln de Read the PT100 values every five minutes 0 59 5 usr bin read_pt100 Fill 00 04 10 16 22 usr bin fill auto ai a3 a4 c1 c2 c3 gt dev null The last line is the only one which you should ever change Note that the mail address here is for cron errors not fill system errors so don t change it The first value in the last line 00 means that the fill takes place at zero minutes past the hour The second entry 04 10 16 22 indicates that fills occur at 4 AM 10 AM 4 PM and 10 PM So if you want to change the fill times that is the place to do it The only other thing which you should change is the list of outlets al a3 a4 c1 c2 c3 in the example to be filled The auto must be there and is used to let the fill program know that this is a scheduled automatic fill rather than a manual one Don t change it The pipe to dev null should also not be changed It is to stop the fill program sending messages back to cron The
11. ectly on all the outlets Look at the individual outlet status to see whether filling was successful Possible values for the program status are INITIALISING it crashed before it even got properly started e KILLED it received a signal This could be a control C issued from the keyboard an explicit kill or a serious program failure such as a segmentation violation e PURGING it failed during the purge e FILLING it failed during the fill e HARDWARE_ERROR it could not speak to the manifold properly e KEY_ERROR the key was in the manual position so it couldn t do anything at all e PURGE_TIMEOUT the maximum purge time was reached without seeing any LN2 at the outlet Probably the LN2 vessel was empty e SUCCESS the program terminated at the end of its fill cycle whether or not the fill succeeded e OUTLET_ERROR one or more of the outlets failed to fill correctly causing the program to terminate prematurely Possible values for the outlet status are e DONE all OK and everything is fine e PURGE it was purging the manifold when it failed e WAIT_LN2 it was waiting for LN2 at the detector outlet when it failed e GOT_LN2 it got LN2 at the detector and failed when it tried to close the valve e WAIT_DRY it got LN2 at the detector outlet and closed the valve but failed before the LN2 stopped flowing e ABORT the program was terminated due to an error condition e IGNORE the program was not told t
12. he file emergency_fill_disabled sh can be used to disable emergency fills but there is also another file all_fill_ disabled sh which has the same format but disables all fills on that outlet including automatic and manual fills This is intended only for use by automatic scripts which detect a PT100 temperature high enough that it is not desirable to cool the detector back down again without first pumping on it If you try to fill an outlet disabled in all_fill_disabled sh the fill program will write an error message to standard error and ignore the request though it will fill any other outlets requested which are not disabled 11 E mail lists The autofill system uses four e mail aliases which are defined in the files home miniball alias_af tat They are e af_sms for sending SMS messages via an e mail to SMS gateway e af_emerg for sending emergency messages e af_warn for sending warning messages e af_info for sending the normal log files after each fill The format of this file is a comma separated list of e mail addresses Note that the format is critical as if it is wrong nobody gets any e mail 12 PT100 calibration The file home miniball autofill pt100_cal dat has the offset and gain for the calibration of each PT100 Typically the offset is around 18 and the gain around 0 44 but it may be desirable to adjust the offsets for individual PT100s to allow for slightly different calibrations Note that you can disable the PT100 rea
13. lets to fill at that time It takes the information from the active crontab and writes it back when you press return or click on Save The GUI doesn t allow you to select the number of minutes past the hour that it fills at and always fills at the top of the hour If you really need to change the minutes you ll have to enter the crontab manually see section 6 Clicking on Status pops up a window which displays the status of the valves and sensors Clicking on Manual fill pops up a window in which you can give the list of outlets to fill e g al a2 cl Give them separated by spaces Finally in the top right corner there is a picture of a polar bear which does nothing at all 4 Monitoring the filling system You can find out what the current status is by issuing the commands show_pt100 to see the temperatures and show_last_fill to show the last fill status This information is also sent to the af_info e mail list after each fill The system also generates plots which it stores in the home warr www directory If we could run a web server it would be possible to view them over the Internet 4 1 show_pt100 This command gives a temperature for each outlet and the time that this temperature was recorded The time should be within the last five minutes or so The output is like Outlet Temp Timestamp Al 92 0 K Thu Jan 9 09 10 01 2003 A3 99 4 K Thu Jan 9 09 10 01 2003 A4 97 0 K Thu Jan 9 09 10 02 2003 C1 97 8 K Thu Jan
14. o fill this outlet this shouldn t appear in a log entry e FAILED it failed to fill that outlet All except DONE are error conditions and should not be ignored 4 3 The system log var log messages The fill program writes messages to standard output when called from the command line and in all cases writes messages to the system log file var log messages 4 4 xv home warr www temps png This command plots the evolution of the temperatures over the previous week as a function of time graphi cally 4 5 xv home warr www 2days png This command plots the evolution of the temperatures over the previous 48 hours as a function of time graphically 4 6 xv home warr www durations png This command plots the filling duration as a function of time graphically If the filling time rises it could be either that the threshold of the LN2 sensor needs adjusting or that the LN2 line is icing up Look at it while it is filling and if the LN2 detect light on the manifold control box doesn t come on as soon as LN2 starts flowing properly the potentiometer needs adjusting with a screwdriver If that is fine there is probably ice in the line so thaw it out and let the water out 5 Monitoring the system from the web The outputs of show_pt100 show_last_fill and the temperature and fill duration plots are periodically copied to http www ikp uni koeln de warr pt100 html You should check the timestamps on the fill and PT100 times to make sur
15. o graphical mode 2 Nomenclature The manifolds have letters A B C and D The outlets are specified by the letter of the manifold and the number of the outlet on that manifold e g Al A2 C3 etc 3 Using the Graphical User Interface Start the GUI by clicking on the button marked Autofill on the console of the filling computer or use the command af_config from the command line The three main regions of the display show the last fill status the same as with the show_last_fill com mand described in section 4 2 below the detector temperatures as measured by the PT100s the same as with show_pt100 command also described in section 4 1 below and the log messages from the system log file var log messages see section 4 3 In the middle there are buttons for each outlet Red buttons indicate that emergency fills triggered by either the absolute value of the temperature or by temperature rises are disabled whereas green buttons indicate that emergency fills are enabled for that outlet Click to toggle between these two states The buttons in the middle are used to plot a graph of the temperature vs time plot a graph of fill duration vs time to configure the filling times to force a manual fill to display the valve and sensor status or to quit Clicking on configure times opens up a window with two colums On the left is the list of hours at which the fills should take place e g 04 12 20 and on the right the list of out
16. the pressure is between 1 5 and 2 bar If there is LN2 and no pressure check that you don t have a leak If you get an error message ERROR fill disabled on A1 or another outlet this means that this outlet is disabled in the all_fill_disabled sh file If you the LEDs on the manifold control boxes for the manifold are off they should normally either be red closed or green open but never off check that the manifolds have power and that the cables are connected If they are OK it might be one of the two 0 5 Amp fuses inside the manifold control box Note that there are three fuses for this box and only one is accessible from the back The other two are inside If any LEDs are lit at all the one at the back is OK We have had ones inside the control box blow on a couple of occasions 14 Switching between systems This section explains how to switch between the old pcepsc22 and the new pcepuis20 filling computers The autofill computer not only controls the autofill but it also monitors the UPS and controls the high voltage The UPS is connected via a serial cable which should be plugged into the filling computer directly The HV is controlled by a private network which plugs into the second ethernet controller of the filling computer Both pcepsc22 and pcepuis20 have second ethernet controllers the primary one being connected to the normal CERN network The second controller of whichever computer is to control the HV should
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