SPS Timing

Outline Timing table Modes of operation Mode switch mechanism External events Creating a timing table Timing event cleaning

Timing tables Set of events needed for a given supercycle Event header:event name:cycle name:occurrence:absolute timing:nibble code #corresponding event code

Timing tables The timing table is loaded in the MTG which translate it into basic commands : WAITA, JUMPA, INIT,SEND…

Modes of operation (1) SPS modes of operation SPS –Pulsed : 8000 –Full economy : 1000 –Partial economy : 400 –Prepare/ recover coast: 400 and 1000 –Coast : 200 and 800 –Shut down : 2000 –Pulse start/stop : 4000 The same code is used for “economy” mode and “prepare/recover coast” mode. A same timing table covers either the economy mode or the coast mode.

Modes of operation (2) The nibble code, defined in the timing table for each event, is the hexadecimal sum of the mode’s code in which the event has to be distributed. This nibble codes are used by the MTG to create, from the timing table, 7 sub-tables with the needed events for each mode of operation. A particular kind of events, the markers, are used as switches from one sub-table to an other.

Mode switch mechanism : pulsed mode

Mode switch mechanism : full economy mode Switch to economy modes : –Each beginning of supercycle, MTG reads intensity : if lower than a defined threshold, the MTG switch to the full economy table if the MD request is desable. The marker 1802 is disable.

Mode switch mechanism : partial economy mode Switch to economy modes : –Each beginning of supercycle, MTG reads intensity : if lower than a defined threshold, the MTG switch to the partial economy mode if the MD request is enable. The marker 1802 is disable.

Operator can force the economy or pulsed mode with the MTG control application.

Mode switch mechanism : coast and prepare/recover mode Operator triggers the MD coast by sending a command “store-2” to the MTG. The MTG switch to the corresponding prepare/recover mode then to the store mode. The store mode is played until the MTG receive a command “recover-0” and switch to prepare/recover mode again

Mode switch mechanism : coast and prepare/recover mode

Mode switch mechanism : pulse stop/start and shutdown mode MTG external events.

External events : EDF and MPS (slides from JM Bouché)

Create a timing table: templates files A template file define a set of events, with a common function, for a given type of cycle. The events in templates are not defined with their absolute timing in supercycle but with their delay from key events (injection, extraction, beam out…) The nibble code for each event is also defined in the template.

Template example 1

Template example 2

Template example 3

Create a timing table: make_mtgtab script Definition of the elementary cycle with the key events and the templates to be used.

Create a timing table: make_mtgtab script Definition of the supercycles with their length, the elementary cycle their start time

Timing events cleaning Motivations The timing system is very flexible : for any special request, a new template is created or a new cycle in the script file. Becomes difficult to generate timing table automatically, script file is bigger and bigger. Old hardware constraints are not valid anymore. The generation of SPS timing event by the CBCM will be impossible without a rationalization and a clear policy of the events.

Timing events cleaning done during this run Removal of almost all old timing event with “oldmtg” header. (still 6 in use), and some other unused events. Working group with major timing users to review the existing events and understand the software and hardware constraints. Define a clear policy for the events generations to feet the CBCM policy.

Timing events cleaning to be done during shutdown Generate timing tables with new policy : –Last 2 bytes have to be used only for cycle id and occurrence. (big change for power supplies events) –A cycle id different for proton LHC, proton FT, proton CNGS, ion FT and ion CNGS. A cycle id has to be the same for all the events belonging to the same cycle. –Define virtual events to follow the CBCM policy.

Conclusion The timing modification will imply some hardware and software modifications for the equipment groups. Some particular events will be difficult to remove or make conform to the new policy. It has to be studied case by case. In December a test will be done with timing tables conform to the new policy, still generated with SPS MTG, to check any problem before the switch to the CBCM.