S800 Documentation

User Tools

Site Tools

Trace:
trigger

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision 		Previous revision
Next revision Both sides next revision
trigger [2013/12/26 13:29]
pereira [Trigger module] 		trigger [2014/03/11 11:20]
pereira [Scalers and dead time]
Line 84: Line 84:
  
 ====== Time stamping ====== ====== Time stamping ======
-The S800 trigger provides a vetoed 10 MHz clock signal (derived from the 40 MHz FPGA clock) used for time stamping. An external clock can also be used, after selecting the appropriate check box in the [[Trigger#Trigger Schematic|GUI]]). The clock is inhibited by a "Go" signal controlled by the trigger module. While "Go" is false, all time stamp counters can be reset via CAMAC command, typically during the begin sequences of the controllers or data acquisitions (see section "[[Trigger#Begin sequence|Begin sequence]]"). The clock signal is released when the "Go" signal is set to true at the end of the begin sequence. This simple scheme insures that all time stamp counters are synchronized. +The S800 trigger provides a vetoed 10 MHz clock signal (derived from the 40 MHz FPGA clock) used for time stamping. An external clock can also be used, after selecting the appropriate check box in the [[Trigger#Trigger Schematics|GUI]]). The clock is inhibited by a "Go" signal controlled by the trigger module. While "Go" is false, all time stamp counters can be reset via CAMAC command, typically during the begin sequences of the controllers or data acquisitions (see section "[[Trigger#Begin sequence|Begin sequence]]"). The clock signal is released when the "Go" signal is set to true at the end of the begin sequence. This simple scheme insures that all time stamp counters are synchronized. 
  
 The time stamping clock is available as an output that can be distributed to other time stamp modules, such as the one located in the S800 VME crate, or in other data acquisition systems coupled to the S800.  The time stamping clock is available as an output that can be distributed to other time stamp modules, such as the one located in the S800 VME crate, or in other data acquisition systems coupled to the S800. 
Line 157: Line 157:
 In addition, scalers are connected to the raw and live trigger signals. For the determination of the dead time, both a free running and vetoed 10 kHz pulser signal are also connected to scalers. This is the preferred method because the pulser is not subject to possible double triggering effects like the raw trigger.  In addition, scalers are connected to the raw and live trigger signals. For the determination of the dead time, both a free running and vetoed 10 kHz pulser signal are also connected to scalers. This is the preferred method because the pulser is not subject to possible double triggering effects like the raw trigger. 
  
-The list below is a direct copy of the scaler description file for the s800. This file maps channel names to channel numbers, and in addition determines the layout.+The remining 16 scaler input channels (pins 17 to 32 in module) are connected to a **16-channel CFD CAEN C808**, which sends the signals from the S800 detectors (**E1 up,** **E1 down**, **CRDC1**, **CRDC2**, **OBJ_SCI**, **A1900 SCI**, and **OR Hodoscope**).  
 + 
 +The list below is a direct copy of the scaler description file for the s800. This file maps channel names to channel numbers, and in addition determines the layout.  
  
 ^ Channel name ^ Channel number ^ Channel name ^ Channel number | ^ Channel name ^ Channel number ^ Channel name ^ Channel number |
Line 177: Line 180:
 | S800.Source   ^ 0 | XFP.Scint      ^ 25 | | S800.Source   ^ 0 | XFP.Scint      ^ 25 |
 | Hodo.OR       ^ 30 |                ^  |  | Hodo.OR       ^ 30 |                ^  | 
 +
 +In principle, it is possible to include other signals into the scaler channels that are not used. This requires some manipulation of tcl scripts, according to the following steps:
 +
 +
 +  * Modify the scaler display script to include the new signals: Go to **/user/s800/Documents/Run/scalers/USBDAQ** and edit file **s800scl.des** to include the new channels (make sure that you make a copy of the old file so that it can be recovered when the new signals are not needed anymore). Save the new file.
 +
 +  * Connect the new logic signals into the free input channels of the 1**6-ch CFD CAEN C808.** Follow the output ribbon cable to know the corresponding scaler channel where the new signals from the CFD are sent.
 +
 +  * Enable the new CFD CAEN C808 channels (if they are not yet enabled): Go to **/user/s800/operations/daq/usb/Scripts** and edit file C**C0105Begin.tcl**. There ist an array variable **cfd EnableOnlyChannels** that includes the list of enabled channels. Make sure that the new channels are included. Save the new file.
 +
 +  * Start the scalers display script. You should see the new channels in the display counting. If they are zero, the CFD thresholds may be too high. If that is the case, you should lower them in file **s800cfdini.tcl** (directory **/user/s800/operations/daq/usb/Configs**).
 +
 +
 +
  
  
trigger.txt · Last modified: 2023/10/24 16:47 by swartzj

Page Tools

Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Noncommercial-Share Alike 4.0 International
CC Attribution-Noncommercial-Share Alike 4.0 International Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki