[Dsg-rich] Third cable and connector on RICH LV boards' service connector

[Tyler Lemon]

Hello Chris, 

My reply is inline below in blue. 


Hi, 

If the 'hardware interlock system' produces an interlock relay closure, and this closure is the logical OR of several signals, then the closure should be connected to the CAEN mainframe interlock input(CPU). Is this the case? 

For the LV boards, the hardware interlock system will open a relay to break the short circuits required at the service connector to enable a group's output. This is described in on page 7 of the attached manual for the A2518 boards. 

We are not using the interlock input on the CAEN mainframe because when asked, Valery said HV should be turned off before LV. Using the interlock input on the mainframe will shutoff both HV and LV at the same time. 



The interlock signals on the A2518 boards control two groups of 4 low voltage outputs. Each output channel has over-voltage and over-current trip points, 

We are not monitoring any current or voltage output of HV or LV. The hardware interlock system will only disable HV/LV in the event that one of the hardware interlock system sensors (temperature, humidity, N2 flow, cooling airflow, cooling tank pressure) goes out of the determined limits. 

and I do not see the need to interface to each group of LV interlocks if there is a global interlock signal that will latch a disable condition. 

We have programed the hardware interlock system in a way that disables all LV groups at once and all HV channels at once. The hardware interlock system does not disable/enable each individual group. 


Is it really necessary to sequence the shutoff of HV and LV? 
If not, we can change the hardware interlock system code to use the CAEN mainframe interlock input. 

Best regards, 
Tyler 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/dsg-hallb_rich/attachments/20170809/ab77473f/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: A2518_rev8.pdf
Type: application/pdf
Size: 1992539 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/dsg-hallb_rich/attachments/20170809/ab77473f/attachment-0002.pdf>