[Fews] Sniffer PLC problem

[Steve Christo]

Hi Will,
Thanks for the response. It gave me the impetus to recheck the sniffer 
for possible errors. The problem was with the old LN2 level controller. 
The level probe on the large Dewar was giving a bad reading with a 
negative value. This prompted the controller to generate a "failed to 
fill" error. When I jiggled the connector to get a good reading and 
cleared the fault on the controller, the sniffer began operating 
normally. I'm going to look into how to remove the old level controller 
from the loop since it's only there to show us the level in the large 
Dewar.

VNC is no longer allowed and printing over the network has proven to be 
a challenge with the computer center's meddling. I've generated a PDF 
file of the control program and downloaded it to my memory stick for 
study upstairs. The Modbus+ light is still blinking and the red "F"s are 
still on at the PLC module front panels. I will now assume this is their 
normal condition.

I'm still confused with the triggers for the trouble light. It is not 
clear in the program. Is it possible that the program sometimes refers 
to "trouble" and "warning" as the same thing? I'll send the PDF printout 
of the program modules to you later this morning.  Thanks for your help.
Steve

 Will Brooks wrote:
> Hi,
>
> The trouble lamp gets illuminated based on a number of possible 
> conditions. You should be able to search on the variable 
> "trouble_lamp" or something like that in the software and find all the 
> conditions that cause it to be lit. If you can print out the program 
> or save it to a pdf, I can find it. I used to be able to VNC into the 
> PC, but I assume that has been eliminated by now.
>
> That's all assuming the program is working normally.
>
> I think the rapidly blinking Modbus plus light is normal, indicating 
> the network is working ok. I can't remember what the F means, but the 
> manuals for the modules should be nearby. One thing you can check is 
> the DC power supply (little black module, Krister should remember it), 
> I think it's 12 Volts, if it's not working it will result in a trouble 
> condition. However, I wouldn't expect that to keep the sniffer from 
> cycling, most likely the trouble is with the sniffer, probably the LN2 
> filler signal or something like that.
>
> Let me know if you want me to do something, I'm happy to try to help.
>
> Thanks,
>
> - Will
>
>
>
> Steve Christo wrote:
>> The sniffer quit cycling on Friday afternoon, 10/2/09. Installed OS 
>> updates today, rebooted PC, cycled power on PLCs, downloaded fresh 
>> PLC software. The LabView control program is hanging when it waits 
>> for a response to from the PLC when initializing. Am able to 
>> communicate with PLC through "Concept" program, i.e. upload, download 
>> programs, view status, etc.. The Alarm rack shows a persistent lit 
>> yellow "Trouble" light. Krister and I could not figure out what that 
>> means from the PLC software. Also, four of the PLC analog modules are 
>> showing a red "F" on the front panel next to the "Active" light. Two 
>> of the modules are showing a rapidly blinking "Modbus+" light. I 
>> don't know if any of these module conditions is normal. What can make 
>> the "Trouble" lamp to light? Will? John?
>> Steve
>>
>> _______________________________________________
>> Fews mailing list
>> Fews at jlab.org
>> https://mailman.jlab.org/mailman/listinfo/fews
>>   
>