Wiki source code of Trigger Howto

Last modified by sndueste on 2023/07/07 11:28

version	line-number	content
1.1	1
	2
6.1	3	{{toc/}}
1.1	4
10.1	5	= Introduction (user panel)
	6	=
1.1	7
27.1	8	The MTCA based triggers have a jitter in the few ps range, the delay can be shifted in 9 ns steps, One can choose between 10 Hz triggers, Triggers connected to the (fast) FEL shutters, frequencies locked to the pulses (e.g. 1MHz) and the actual bunch patterns. A detailed description can be found at the[[ N.A.T. webpage >>url:https://nateurope.com/product/namc-pstimer/\|\|shape="rect"]].
1.1	9
19.1	10	In short:
1.1	11
19.1	12	* the triggers are for low impedance (~~50 Ohm )
28.1	13	* signal level is:
	14	** + 3 V to + 4.5V for high (actual trigger) and 0V for low (baseline) at 50 Ohm
	15	** + 6 V to + 9V for high and 0V for low at 1 MOhm
30.1	16	** the different trigger levels come from different hardware versions of the trigger hardware ... (4.5 V new, 3 V old)
28.1	17	** one can also invert the signal in the expert panel ( thus the base line is + (3-5) V and the actual trigger signal is 0V)
24.1	18	* The trigger are send to the MTCA several ms before the first FEL pulse (3.1 ms for the "standard" trigger, 21.5 ms for the "early" trigger).
19.1	19	* The timer card can delay the trigger in 9 ns steps for more than 100 ms (an option to shift the trigger in 1 ns steps is available in the expert panel)
	20	* The shown delay in µs is in respect to the //first// FEL pulse. negative delay: trigger comes before FEL, positive : trigger comes after the FEL.
	21	* The desired delay has to be entered in the "delay to be set" field and as second step pressing the "set delay" sends the delay value to the timer card. Then the trigger delay will be changed and the "actual delay" will be updated.
	22	* The trigger can be set to only provide a trigger signal if the FEL Fast shutter is open. One has to choose which FEL shutter to use.
	23	* The trigger width can be adjusted from 9 ns to several ms in 9 ns steps
	24	* The timer card can in addition to the 10 Hz triggers also provide frequencies which are linked to the FEL repetition rate and the actual burst pattern of the FEL. For details how to set these modes see below
	25	* At the beamlines the triggers are provided with a BNC patch panel
1.1	26
19.1	27	The main control can be done with a simplified user panel which can handle the timing in respect to the FEL pulses (and not in respect to some arbitrary event time)
	28
	29
1.1	30	\\
	31
20.1	32	[[image:attach:image2020-1-23_12-10-59.png\|\|width="700"]]
19.1	33
	34	\\
	35
	36	\\
	37
22.1	38	Choosing a FLASH1 trigger there are 2 options to be synchronized with the BL and the PG shutter :
21.1	39
22.1	40	[[image:attach:image2020-1-23_12-29-40.png\|\|height="250"]]
21.1	41
22.1	42	A yellow background indicates that the trigger is synchronized to a fast shutter:
	43
	44	[[image:attach:image2020-1-23_12-31-41.png\|\|height="250"]] or:[[image:attach:image2020-1-23_12-32-20.png\|\|height="250"]]
	45
19.1	46	\\
	47
	48	\\
	49
1.1	50	\\
	51
6.1	52	= Expert panels =
1.1	53
	54	\\
	55
21.1	56	[[image:attach:image2020-1-23_12-28-6.png\|\|height="250"]] [[image:attach:image2019-9-17_13-8-46.png\|\|height="400"]]
6.1	57
7.1	58	With the "Expert overview" one gets the overview over all channels available on the timing card and can configure the card. This is useful to look what channels are using clock settings or burst mode settings that one wants to change ... and using the other tabs one can set parameters for clocks and bursts (see below)
6.1	59
	60	\\
	61
7.1	62	For each trigger channel there is in addition an "Expert panel" to set the properties of THIS channel
6.1	63
21.1	64	[[image:attach:image2020-1-23_12-28-46.png\|\|height="250"]] [[image:attach:image2019-9-17_13-15-38.png\|\|width="550"]]
6.1	65
	66	\\
	67
	68	\\
	69
10.1	70	= Set a constant frequency to a channel =
	71
	72	=
6.1	73	[[image:attach:image2019-9-17_13-18-9.png\|\|height="250"]][[image:attach:image2019-9-17_13-18-37.png\|\|height="149"]] =
	74
	75	\\
	76
7.1	77	The timer card provides the option to generate frequencies that are synched to the FEL reprate on the ps level. One can set 3 Clocks by deviding the reference frequency of 54.2 MHz by n. Please check (using the Expert overview ) before changing a frequency of it is used for some other channel !!
6.1	78
	79	Since our main FEL frequency is 100.31 MHz the dividers are not straight forward:
	80
10.1	81	[[image:attach:image2019-9-17_14-22-29.png\|\|width="450" align="right"]]
	82
	83	\\
	84
7.1	85	(% class="wrapped" %)
6.1	86	\|=(((
	87	Clock frequency
	88	)))\|=(((
7.1	89	Divider to be set
6.1	90	)))
	91	\|(((
	92	"1 MHz" (1000.31 kHz)
	93	)))\|(((
	94	53
	95	)))
	96	\|(((
7.1	97	"500 kHz" (501.5 kHz)
6.1	98	)))\|(((
7.1	99	107
6.1	100	)))
	101	\|(((
7.1	102	"250 kHz" (250.8 kHz)
6.1	103	)))\|(((
7.1	104	215
6.1	105	)))
7.1	106	\|(% colspan="1" %)(((
	107	"200 kHz" (200.6 kHz)
	108	)))\|(% colspan="1" %)(((
	109	269
	110	)))
	111	\|(% colspan="1" %)(((
	112	"100 kHz" (100.3 kHz)
	113	)))\|(% colspan="1" %)(((
	114	539
	115	)))
6.1	116
10.1	117	\\
	118
15.1	119	== General FLASH frequencies: ==
	120
10.1	121	\\
	122
16.1	123	(% class="relative-table wrapped" style="width: 19.422%;" %)
17.1	124	\|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
18.1	125	(% style="color: rgb(0,0,0);" title="" %)**Name
	126	**
17.1	127	)))\|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
18.1	128	(% style="color: rgb(0,0,0);" title="" %)**Frequency
	129	**
17.1	130	)))\|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
	131	(% style="color: rgb(0,0,0);" title="" %)Divider
15.1	132	)))
	133	\|(((
	134	1.3 GHz
	135	)))\|(((
	136	1300.000000 MHz
	137	)))\|(((
10.1	138	\\
15.1	139	)))
	140	\|(((
	141	108 MHz
	142	)))\|(((
	143	108.333333 MHz
	144	)))\|(((
	145	12
	146	)))
	147	\|(((
	148	9 MHz
	149	)))\|(((
	150	9.02777777 MHz
	151	)))\|(((
	152	144
	153	)))
	154	\|(((
	155	4.5 MHz
	156	)))\|(((
	157	4.513888 MHz
	158	)))\|(((
	159	288
	160	)))
	161	\|(((
	162	1 MHz
	163	)))\|(((
	164	1.003086 MHz
	165	)))\|(((
	166	1296
	167	)))
10.1	168
	169	\\
	170
7.1	171	Once a clock is configured with the right frequency one can choose in the "expert panel" of the according channel the "FPGA clock" in the "input source select" chooser.
	172
10.1	173	One has to set the delay to values less than the repetition rate ... (so for 1 MHz between 0 and 990 µs) and the trigger width also less than the rep rate ...
8.1	174
15.1	175	This results in a continuous train of pulses with the set trigger width.
8.1	176
10.1	177	= Creating an (own) burst trigger =
	178
	179	One can use now a SECOND trigger channel which is set to a regular 10 Hz trigger and gate the clock output to create a burst with defined start point and length,
	180
11.1	181	For the example we use the FRONT.TRG2 (BL3 Trg5) as gate pulse which defines the length of the burst (set with the trigger width) and the (rough) starting point of the burst. This trigger is only used as gate and the physical trigger output is NOT used.
10.1	182
11.1	183	The second channel (here FRONT.TRG3 (BL3 Trg6) which is set to the clock frequency defines the reprate (by the FPGA clock setting) , the exact starting point of the first trigger ( by the delay ) and the width of the MHz/kHz triggers (width).
10.1	184
11.1	185	To get from the clock to the burst trigger one has to:
10.1	186
11.1	187	* set the "2nd source select" to the gate trigger ( here FRONT.TRG2) - this defines a second source to considder for the trigger output.
	188	* and the "output source select" to "AND 2nd Ch." this finally only sends a trigger if on both inputs (clock and gate) we have a high signal.
	189
10.1	190	\\
	191
11.1	192	[[image:attach:image2019-9-17_14-35-5.png\|\|height="250"]] [[image:attach:image2019-9-17_14-34-38.png\|\|width="400"]]
	193
10.1	194	\\
	195
	196	\\
	197
11.1	198	= Real bunch trigger - get a trigger for each FEL pulse =
	199
10.1	200	\\
	201
11.1	202	Sometimes it is convenient to get a trigger pulse for each pulse in the FEL. thus if the FEL number of bunches or reprate are changed, the trigger adapts accordingly.
1.1	203
11.1	204	For this one has to select the source of interest in the expert overview panel (tab: "Bunch pattern") ... well for us this is FLASH1 (FL1D) or FLASH2 (FL2D)
1.1	205
11.1	206	There are 6 different bunch pattern "channels" one can configure. Typically only 2 are needed ... And in each one there are 6 selectors to choose sources . We only need one - it does not matter in which one is used.
1.1	207
12.1	208	[[~[~[image:attach:image2019-9-17_14-51-28.png~\|~\|height="250"~]~]>>attach:image2019-9-17_14-51-28.png]][[image:attach:image2019-9-17_14-47-15.png\|\|thumbnail="true" height="199"]]
8.1	209
	210	\\
	211
11.1	212	In the expert panel one can now choose the configured "Bunch Pattern" as "Input source select"
10.1	213
11.1	214	NOTE: To shift the burst in time one can no longer use the delay of the individual channel BUT the delay in the "Bunch pattern" tab in the expert overview! This now shifts all bursts ... so you better know what you are doing. typically the burst is already shifted to the actual FEL timing ... Shifting the timing should be discussed with the beamline scientist / local contact ...
	215
10.1	216	\\
	217
13.1	218	[[image:attach:image2019-9-17_15-4-47.png\|\|height="250"]][[image:attach:image2019-9-17_14-52-40.png\|\|height="250"]]
11.1	219
10.1	220	\\
	221
	222	\\
	223
20.1	224	= Different trigger events (starting points) =
	225
	226	one can configure each channel for an individual trigger event
	227
	228	FLASH1
	229
21.1	230	(% class="wrapped" %)
20.1	231	\|(((
	232	trigger No
	233	)))\|(((
	234	function
	235	)))
	236	\|(% colspan="1" %)(((
	237	21
	238	)))\|(% colspan="1" %)(((
	239	Trig16 + first bunch of FLASH1 - this trigger is shifted when FL1 starts later than "700"
	240	)))
	241	\|(% colspan="1" %)(((
	242	180
	243	)))\|(% colspan="1" %)(((
	244	shifts with the start time of FLASH1 as event 21 but comes 23 ms before the FEL
	245	)))
	246	\|(((
	247	16
	248	)))\|(((
	249	the MCA trigger 3.11 ms before the Flash1 pulses (same as A6 but more stable)
	250	)))
	251	\|(((
	252	166
	253	)))\|(((
	254	A6 event. still possible to use but less precise than 16
	255	)))
	256	\|(((
	257	162
	258	)))\|(((
	259	A2 event as earliest ( 24 ms before the FEL)
	260	)))
	261	\|(((
	262	224
	263	)))\|(((
	264	E0 event of the BL fast shutter ( 19 ms before the FEL) - to be switched off in 2020
	265	)))
	266	\|(((
	267	225
	268	)))\|(((
	269	E1 event of the PG fast shutter ( 19 ms before the FEL) - to be switched off in 2020
	270	)))
	271
10.1	272	\\
	273
	274	\\
	275
20.1	276	FLASH2
	277
21.1	278	(% class="wrapped" %)
20.1	279	\|(((
	280	trigger No
	281	)))\|(((
	282	function
	283	)))
	284	\|(((
	285	22
	286	)))\|(((
	287	Trig116 + first bunch of FLASH2 - this trigger is shifted when FL2 starts at a different start time
	288	)))
	289	\|(((
	290	181
	291	)))\|(((
	292	shifts with the start time of FLASH2 as event 22 but comes 23 ms before the FEL
	293	)))
	294
	295	from this trigger as starting point one can shift the timing in 9 ns steps first and finally in 0.9 ns steps for fine adjustment.
	296
10.1	297	\\
	298
	299	\\
	300
23.1	301	= Info about the Fast shutter trigger =
10.1	302
23.1	303	Since Jan 2020 the fast shutter trigger at FLASH1 is generated via local inhibit at the EXP1 and EXP2 crate and not via E0 and E1 events anymore
	304
	305	for details see [[doc:FLASH.Fast Shutter trigger inhibit system]]
	306
10.1	307	\\
20.1	308
25.1	309	== Special trigger options for the fast shutter: ==
	310
	311	=== Fast shutter inhibit signal ===
	312
26.1	313	It is possible to have the fast shutter inhibit signal (the signal coming from the fast shutter to the inhibit boxes connected to the X2 cards) directly available for users. For this one can select the output source as 2nd channel:
25.1	314
26.1	315	[[image:attach:image2020-2-5_10-59-41.png\|\|height="250"]]
	316
20.1	317	\\
	318
26.1	319	=== Inverse fast shutter trigger ===
25.1	320
26.1	321	If one wants to have an inverse fast shutter trigger (10 Hz signal that comes only if the fast shutter is CLOSED) one can use a T and a small Lemo cable to double the input from the fast shutter to another input at the inhibit box.
	322
	323	In the FL2 case input1 is the regular fast shutter channel and input2 is usually not used. for this additional input one can set the input configuration to inverse:
	324
	325	[[image:attach:image2020-2-5_14-11-55.png\|\|height="400"]]
	326
20.1	327	\\
	328
30.1	329	= Some expert infos =
	330
	331	== how to find details (age ...) of the timer cards / RTMs ==
	332
	333	[[image:attach:Capture.PNG\|\|height="250"]][[image:attach:Capture1.PNG\|\|height="250"]][[image:attach:Capture2.PNG\|\|thumbnail="true" height="250"]]
	334
31.1	335	== Info about the trigger levels of the RTMs ==
	336
	337	3V RTMs: (Status July 2023)
	338
	339	* FLASH.FEL/TIMER/EXP2/RTM... (BL3)
	340	* FLASH.FEL/TIMER/EXP2.1/RTM... (fast shutter monitor ..)
	341	* FLASH.FEL/TIMER/EXP1.1/RTM... (new for PG1)
	342	* FLASH.FEL/TIMER/FL2EXP1.1/RTM... (FL24)
	343
20.1	344	\\
	345
31.1	346	4.5V RTMs: (Status July 2023)
	347
	348	* FLASH.FEL/TIMER/EXP1/RTM... (BL1)
	349	* FLASH.FEL/TIMER/FL2EXP1/RTM... (FL26)
	350	* FLASH.FEL/TIMER/THZSTR1/RTM... (FL21)
	351
20.1	352	\\
	353
	354	\\
25.1	355
	356	\\
30.1	357
	358	\\
	359
	360	\\
31.1	361
	362	\\
	363
	364	\\