Wiki source code of Trigger Howto

Last modified by sndueste on 2023/07/07 11:28
Show last authors
1
2
3 {{toc/}}
4
5 = Introduction (user panel)
6 =
7
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"]].
9
10 In short:
11
12 * the triggers are for low impedance (~~50 Ohm )
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
16 ** the different trigger levels come from different hardware versions of the trigger hardware ... (4.5 V new, 3 V old)
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)
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 * 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
26
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
30 \\
31
32 [[image:attach:image2020-1-23_12-10-59.png||width="700"]]
33
34 \\
35
36 \\
37
38 Choosing a FLASH1 trigger there are 2 options to be synchronized with the BL and the PG shutter :
39
40 [[image:attach:image2020-1-23_12-29-40.png||height="250"]]
41
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
46 \\
47
48 \\
49
50 \\
51
52 = Expert panels =
53
54 \\
55
56 [[image:attach:image2020-1-23_12-28-6.png||height="250"]] [[image:attach:image2019-9-17_13-8-46.png||height="400"]]
57
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)
59
60 \\
61
62 For each trigger channel there is in addition an **"Expert panel"** to set the properties of THIS channel
63
64 [[image:attach:image2020-1-23_12-28-46.png||height="250"]] [[image:attach:image2019-9-17_13-15-38.png||width="550"]]
65
66 \\
67
68 \\
69
70 = Set a constant frequency to a channel =
71
72 =
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
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 !!**
78
79 Since our main FEL frequency is 100.31 MHz the dividers are not straight forward:
80
81 [[image:attach:image2019-9-17_14-22-29.png||width="450" align="right"]]
82
83 \\
84
85 (% class="wrapped" %)
86 |=(((
87 Clock frequency
88 )))|=(((
89 Divider to be set
90 )))
91 |(((
92 "1 MHz" (1000.31 kHz)
93 )))|(((
94 53
95 )))
96 |(((
97 "500 kHz" (501.5 kHz)
98 )))|(((
99 107
100 )))
101 |(((
102 "250 kHz" (250.8 kHz)
103 )))|(((
104 215
105 )))
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 )))
116
117 \\
118
119 == General FLASH frequencies: ==
120
121 \\
122
123 (% class="relative-table wrapped" style="width: 19.422%;" %)
124 |(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
125 (% style="color: rgb(0,0,0);" title="" %)**Name          
126 **
127 )))|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
128 (% style="color: rgb(0,0,0);" title="" %)**Frequency                
129 **
130 )))|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
131 (% style="color: rgb(0,0,0);" title="" %)**Divider**
132 )))
133 |(((
134 1.3 GHz
135 )))|(((
136 1300.000000 MHz
137 )))|(((
138 \\
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 )))
168
169 \\
170
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
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 ...
174
175 This results in a continuous train of pulses with the set trigger width.
176
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
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.
182
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).
184
185 **To get from the clock to the burst trigger** one has to:
186
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
190 \\
191
192 [[image:attach:image2019-9-17_14-35-5.png||height="250"]] [[image:attach:image2019-9-17_14-34-38.png||width="400"]]
193
194 \\
195
196 \\
197
198 = Real bunch trigger  - get a trigger for each FEL pulse =
199
200 \\
201
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.
203
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)
205
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.
207
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"]]
209
210 \\
211
212 In the expert panel one can now choose the configured "Bunch Pattern" as "Input source select"
213
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
216 \\
217
218 [[image:attach:image2019-9-17_15-4-47.png||height="250"]][[image:attach:image2019-9-17_14-52-40.png||height="250"]]
219
220 \\
221
222 \\
223
224 = Different trigger events (starting points) =
225
226 one can configure each channel for an individual trigger event
227
228 **FLASH1**
229
230 (% class="wrapped" %)
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
272 \\
273
274 \\
275
276 **FLASH2**
277
278 (% class="wrapped" %)
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
297 \\
298
299 \\
300
301 = Info about the Fast shutter trigger =
302
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
307 \\
308
309 == Special trigger options for the fast shutter: ==
310
311 === Fast shutter inhibit signal ===
312
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:
314
315 [[image:attach:image2020-2-5_10-59-41.png||height="250"]]
316
317 \\
318
319 === Inverse fast shutter trigger ===
320
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
327 \\
328
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
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
344 \\
345
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
352 \\
353
354 \\
355
356 \\
357
358 \\
359
360 \\
361
362 \\
363
364 \\