This breif document (see mulan folder Run2003 ..) will describe the mulan/flight simulator system so that the flight simulator program can be used to pulse the LEDs imbedded in the detector. The hardware for the flasher system consists of the following:
•Flight simulator, FS, to send ecl triggers out from the DAQ
•BU clock scaled down (2MHz=250ns pulse width)
•ecl/TTL converter= >TTL out for drivers.
•Driver boxes that provide power and pass the trigger to Flashers
•old 2002 drivers with new front panels
•12 lemo inputs (trigger)
•6 10 pin connectors (1 per det. Pair)
•10 pin Jamaican ribbon cables to detector lids
•LED flashers imbedded in the detectors
The wiring for the system has become a bit complicated due to the lid connectors and the combination of two LED flashers on the same cable. There is a diagram on the JMU web page (also see logbook pg 28) . Most of the cabling should not need to be redone. The only cable that may need to be changed is the cable from driver to house. The driver has a polarized plug. Not all of these connectors were connected in the same orientation but the cable can only be attached to the driver one and only one way. The houses, however, have no safeguard and they can be plugged in backwards. Most houses have been marked with a triangle to show which side is pin 1 and which connector to use. The cables indicate pin 1 using a triangle. Also all of the ribbon cable has been made with dark brown wire on the pin 1 side. All of the houses have the same plug and orientation but the penthouses are different from the hexhouses. One connector for each dector pair is currently not used. This connector is not connected to anything inside the house.
THEREFORE CAREFUL: The connection to the house lids is important and by mistake can be reversed. Please align the ribbon connectors so that pin 1 (triangles) are on the same side (ie find the mark on the connector on the cable and the mark on the lid). Note only one of the two lid connectors is used. Mistakenly connecting the cable to the other connector causes no problems.
( Brief overview of the general DAQ can be found at the end. These are just my notes as I was learning about the configuration.)
In order to change and operate the FS one needs to connect to the DAQ through the midas webpage. (Tim G. left general DAQ notes and there are MIDAS doc pages available).
To get the system running you nay need to refer to other documentation.
The FS is a VME module that requires an external clock input. We are currently using aTTL clock. The signal comes from the clock divider and was set to 2 Mhz. (Kevin says the clock shape is not critical.). There are two 34 pin ribbon connectors that provide the FS output. The DAQ loads a 32x 32k memory with 1's and 0's. The DAQ then signals the FS to readout the memory. On each external clock cycle the next 32 bit word is loaded into a register which presents the signals to the 32 outputs (16 per cable) via the two ribbon cable connectors. The duration of the output is ½ a clock cylce. 1's generate pulses.
The flight simulator modules are defined in the VME by their base address and the crate frontend . The base address of the current FS is E02 ( Found in the MIDAS ODB as /Equipment / FSfire /Settings/fs01/Base Address).
To control the flight simulator you need to start the front end program running. The MIDAS framework will basically call the required routines imbedded in the c-code written by the user. The fronend FS code is fefs.c located on fe04, or mulanbe at
(Note thefront end and the backend share common directories via NFS mounts. So you can reach the code from any of these machines and therfore can share executables.)
The program is installed so that it is in the periodic operation mode. This means that the DAQ will trigger a FS trigger generation at regular intervals. The code was modified by the Kentucky group. The critical features (so far ascertained by me) ar the
•equipment list setup
•specify periodic mode EQ_PERIODIC
•several other parameters
•routine update load
•cylcles thr ough the FS memory loads trigger patterns.
•intiates the FS readout thereby generating triggers
In order to run the FS program visit the MIDAS program page. Start the fefs program. It should change to green. There are settings that can be changed by clicking on the fefs in the program column. Make sure the program setup has the correct front end and program name use the format below. (Programs/fefs/Start command)
screen -d -m -S fs ssh -l root fe04 -t /home/mulan/muLan/FlightSimulator/fefs -h be01 -e mulan
Once the program is running one can change the parameters of the running program via the ODB. From the status web page click on the equipment name. This leads you to the ODB database in the directory based structure. For more information see other docs. The rest of this document will assume that one can move around the MIDAS pages to find the various ODB data.
For this run we have choose a 2 Mhz frequency (A 200 Mhz divided by 100 in the clock box. Clock divider now routes these to connectors 4,5 top and bottom). This means a new set of pulses every 500 ns. (250 ns in length) . Kevin has adjuste the clock divider panel location 4 & 5 top a& bottom. The table below just lists some of the relevant frequencies and their location in the ODB. The ODB pulse period was chosen to be 5000 and the period was chosen to be 50 ms for illustration. These are adjustable.
Block diagram of the pulser system. The DAQ communicates with the flight simulator. Parameters are availbale through MIDAS to dtermine which detectors fire and their frequency. The clock sets the timing of all triggers. An ecl to TTL converter passes the trigger via short cables to the driver box. The drivers pass triggers and power over the ribbon cable to the flasher boards. Apot on the dirver box sets the LED intensity.
SIMPLE OVERVIEW OF MULAN DAQ
The MULAN system user: mulan
The MIDAS framework can be configured in many ways. For MULAN the backend and front end comuputer play the central role.
mulanbe (ssh mulanbe)
A simplified block diagram show (see below) the relationship between the various DAQ components for the MULAN setup. There are:
•front ends: (black boxes) fe01, fe02,...fe08
•Only using 3&4 this run.
•4 wfd & FS