Changes for page Trigger Howto

Last modified by sndueste on 2023/07/07 11:28
From version 6.1
edited by sndueste
on 2019/09/17 13:36
Change comment: There is no comment for this version
To version 20.1
edited by sndueste
on 2020/01/23 12:15
Change comment: There is no comment for this version

Summary

Details

Page properties
Content
... ... @@ -2,149 +2,298 @@
2 2  
3 3  {{toc/}}
4 4  
5 -= Introduction =
5 += Introduction (user panel)
6 + =
6 6  
7 -The MTCA based triggers have a jitter in the few ps range, the delay can be shifted in 1 ns steps (over many ms), one can choose between 10 Hz triggers, frequencies locked to the pulses (e.g. 1MHz) and the actual bunch patterns. A detailed description can be found in [[x2Timer manual>>attach:x2Timer.pdf]].
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 in [[x2Timer manual>>attach:x2Timer.pdf]] ([[Design Paper>>url:http://ttfinfo2.desy.de/doocs/Timing/CDRv2.2short.pdf||shape="rect"]]).
8 8  
9 -in short: the triggers are for low impedance (~~50 OHM terminated ?? ), 5V triggers with an adjustable width. The main control panel for the x2 timer has the control options for the 3 front modules (connected with a RJ45 cable - connecting to a "trigger box" with 2 trigger exits (Lemo) each) and 8 Lemo exits at the back of the crate. in the BL-beamline case these triggers are connected to the BNC (patch panel) ports at the rack.
10 +In short:
10 10  
11 -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) reference time ( Event)[[~[~[image:url:http://hasfweb.desy.de/pub/Setup/TriggerHowto/Trigger_scheme.gif~|~|alt="Trigger_scheme.gif" width="800"~]~]>>attach:Trigger_scheme.gif]]
12 +* the triggers are for low impedance (~~50 Ohm )
13 +* signal level is + 5V - otherwise 0V (in the expert panel one can also invert the signal - base line is +5 V and trigger 0V)
14 +* The trigger are send to the MTCA several ms before the first FEL pulse (3.1 ms for the "standard" trigger, 23 ms for the "early" trigger).
15 +* 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)
16 +* 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.
17 +* 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.
18 +* 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.
19 +* The trigger  width can be adjusted from 9 ns to several ms in 9 ns steps
20 +* 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
21 +* At the beamlines the triggers are provided with a  BNC patch panel
12 12  
23 +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)
13 13  
25 +
14 14  \\
15 15  
16 -= different trigger events (starting points) =
28 +[[image:attach:image2020-1-23_12-10-59.png||width="700"]]
17 17  
18 -one can configure each channel for an individual trigger event
30 +\\
19 19  
20 -**FLASH1**
32 +\\
21 21  
34 +\\
35 +
36 +\\
37 +
38 +\\
39 +
40 += Expert panels =
41 +
42 +\\
43 +
44 +[[image:attach:image2019-9-17_13-10-56.png||height="250"]] [[image:attach:image2019-9-17_13-8-46.png||height="400"]]
45 +
46 +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)
47 +
48 +\\
49 +
50 +For each trigger channel there is in addition an **"Expert panel"** to set the properties of THIS channel
51 +
52 +[[image:attach:image2019-9-17_13-14-52.png||height="250"]] [[image:attach:image2019-9-17_13-15-38.png||width="550"]]
53 +
54 +\\
55 +
56 +\\
57 +
58 += Set a constant frequency to a channel =
59 +
60 +=
61 +[[image:attach:image2019-9-17_13-18-9.png||height="250"]][[image:attach:image2019-9-17_13-18-37.png||height="149"]] =
62 +
63 +\\
64 +
65 +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 !!**
66 +
67 +Since our main FEL frequency is 100.31 MHz the dividers are not straight forward:
68 +
69 +[[image:attach:image2019-9-17_14-22-29.png||width="450" align="right"]]
70 +
71 +\\
72 +
22 22  (% class="wrapped" %)
23 -|(((
24 -trigger No
25 -)))|(((
26 -function
74 +|=(((
75 +Clock frequency
76 +)))|=(((
77 +Divider to be set
27 27  )))
28 28  |(((
29 -16
80 +"1 MHz" (1000.31 kHz)
30 30  )))|(((
31 -the MCA trigger 3.11 ms before the Flash1 pulses (same as A6 but more stable)
82 +53
32 32  )))
33 33  |(((
34 -166
85 +"500 kHz" (501.5 kHz)
35 35  )))|(((
36 -A6 event. still possible to use but less precise than 16
87 +107
37 37  )))
38 38  |(((
39 -162
90 +"250 kHz" (250.8 kHz)
40 40  )))|(((
41 -A2 event as earliest ( 24 ms before the FEL)
92 +215
42 42  )))
43 -|(((
44 -224
45 -)))|(((
46 -E0 event of the BL fast shutter ( 19 ms before the FEL)
94 +|(% colspan="1" %)(((
95 +"200 kHz" (200.6 kHz)
96 +)))|(% colspan="1" %)(((
97 +269
47 47  )))
48 -|(((
49 -225
50 -)))|(((
51 -E1 event of the PG fast shutter ( 19 ms before the FEL)
99 +|(% colspan="1" %)(((
100 +"100 kHz" (100.3 kHz)
101 +)))|(% colspan="1" %)(((
102 +539
52 52  )))
53 -|(((
54 -21
55 -)))|(((
56 -Trig16 + first bunch of FLASH1 - this trigger is shifted when FL1 starts later than "700"
57 -)))
58 58  
59 59  \\
60 60  
107 +== General FLASH frequencies: ==
108 +
61 61  \\
62 62  
63 -**FLASH2**
64 -
65 -(% class="wrapped" %)
111 +(% class="relative-table wrapped" style="width: 19.422%;" %)
112 +|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
113 +(% style="color: rgb(0,0,0);" title="" %)**Name          
114 +**
115 +)))|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
116 +(% style="color: rgb(0,0,0);" title="" %)**Frequency                
117 +**
118 +)))|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
119 +(% style="color: rgb(0,0,0);" title="" %)**Divider**
120 +)))
66 66  |(((
67 -trigger No
122 +1.3 GHz
68 68  )))|(((
69 -function
124 +1300.000000 MHz
125 +)))|(((
126 +\\
70 70  )))
71 71  |(((
72 -22
129 +108 MHz
73 73  )))|(((
74 -Trig116 + first bunch of FLASH2 - this trigger is shifted when FL2 starts at a different start time
131 +108.333333 MHz
132 +)))|(((
133 +12
75 75  )))
76 76  |(((
77 -181
136 +9 MHz
78 78  )))|(((
79 -shifts with the start time of FLASH2 as event 22 but comes 22 ms ! before the FEL
138 +9.02777777 MHz
139 +)))|(((
140 +144
80 80  )))
142 +|(((
143 +4.5 MHz
144 +)))|(((
145 +4.513888 MHz
146 +)))|(((
147 +288
148 +)))
149 +|(((
150 +1 MHz
151 +)))|(((
152 +1.003086 MHz
153 +)))|(((
154 +1296
155 +)))
81 81  
82 -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.
157 +\\
83 83  
159 +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.
160 +
161 +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 ...
162 +
163 +This results in a continuous train of pulses with the set trigger width.
164 +
165 += Creating an (own) burst trigger =
166 +
167 +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,
168 +
169 +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.
170 +
171 +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).
172 +
173 +**To get from the clock to the burst trigger** one has to:
174 +
175 +* set the  "2nd source select" to the gate trigger ( here FRONT.TRG2) - this defines a second source to considder for the trigger output.
176 +* 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.
177 +
84 84  \\
85 85  
86 -= Expert panels =
180 +[[image:attach:image2019-9-17_14-35-5.png||height="250"]] [[image:attach:image2019-9-17_14-34-38.png||width="400"]]
87 87  
88 88  \\
89 89  
90 -[[image:attach:image2019-9-17_13-10-56.png||height="250"]] [[image:attach:image2019-9-17_13-8-46.png||height="400"]]
184 +\\
91 91  
92 -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)
186 += Real bunch trigger  - get a trigger for each FEL pulse =
93 93  
94 94  \\
95 95  
96 -For each trigger channel there is in addition a expert panel to set the properties of THIS channel
190 +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.
97 97  
98 -[[image:attach:image2019-9-17_13-14-52.png||height="250"]] [[image:attach:image2019-9-17_13-15-38.png||width="550"]]
192 +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)
99 99  
100 -\\
194 +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.
101 101  
196 +[[~[~[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"]]
197 +
102 102  \\
103 103  
200 +In the expert panel one can now choose the configured "Bunch Pattern" as "Input source select"
201 +
202 +**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 ...**
203 +
104 104  \\
105 105  
106 -= Set a constant frequency to a channel
107 -[[image:attach:image2019-9-17_13-18-9.png||height="250"]][[image:attach:image2019-9-17_13-18-37.png||height="149"]] =
206 +[[image:attach:image2019-9-17_15-4-47.png||height="250"]][[image:attach:image2019-9-17_14-52-40.png||height="250"]]
108 108  
109 109  \\
110 110  
111 111  \\
112 112  
113 -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 before changing a frequency of it is used for some other channel !!**
212 += Different trigger events (starting points) =
114 114  
115 -Since our main FEL frequency is 100.31 MHz the dividers are not straight forward:
214 +one can configure each channel for an individual trigger event
116 116  
117 -|=(((
118 -Clock frequency
119 -)))|=(((
120 -Devider to be set
216 +**FLASH1**
217 +
218 +|(((
219 +trigger No
220 +)))|(((
221 +function
121 121  )))
223 +|(% colspan="1" %)(((
224 +21
225 +)))|(% colspan="1" %)(((
226 +Trig16 + first bunch of FLASH1 - this trigger is shifted when FL1 starts later than "700"
227 +)))
228 +|(% colspan="1" %)(((
229 +180
230 +)))|(% colspan="1" %)(((
231 +shifts with the start time of FLASH1 as event 21 but comes 23 ms  before the FEL
232 +)))
122 122  |(((
123 -"1 MHz" (1000.31 kHz)
234 +16
124 124  )))|(((
125 -53
236 +the MCA trigger 3.11 ms before the Flash1 pulses (same as A6 but more stable)
126 126  )))
127 127  |(((
128 -\\
239 +166
129 129  )))|(((
130 -\\
241 +A6 event. still possible to use but less precise than 16
131 131  )))
132 132  |(((
133 -\\
244 +162
134 134  )))|(((
246 +A2 event as earliest ( 24 ms before the FEL)
247 +)))
248 +|(((
249 +224
250 +)))|(((
251 +E0 event of the BL fast shutter ( 19 ms before the FEL) - to be switched off in 2020
252 +)))
253 +|(((
254 +225
255 +)))|(((
256 +E1 event of the PG fast shutter ( 19 ms before the FEL) - to be switched off in 2020
257 +)))
258 +
135 135  \\
260 +
261 +\\
262 +
263 +**FLASH2**
264 +
265 +|(((
266 +trigger No
267 +)))|(((
268 +function
136 136  )))
270 +|(((
271 +22
272 +)))|(((
273 +Trig116 + first bunch of FLASH2 - this trigger is shifted when FL2 starts at a different start time
274 +)))
275 +|(((
276 +181
277 +)))|(((
278 +shifts with the start time of FLASH2 as event 22 but comes 23 ms  before the FEL
279 +)))
137 137  
281 +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.
282 +
138 138  \\
139 139  
140 140  \\
141 141  
142 -* in order to generate a stable frequency one has to set the input source to FPGA clock (and use dividers to get the desired frequency)
143 -* to generate the burst patterns of the FEL one has to choose a trigger event (best 116 for FLASH 2 and 16 for FLASH1) and activate Destination 1 for FLASH1 and Destination 2 for FLASH2 . finally one has to assign the activated Bunch pattern mask to the trigger channel of choice . now the pattern can be shifted and the trigger width can be changed as with the 10 Hz triggers. **IMPORTANT: to move the bunchtrain to the desired starting point the DELAY in the expert panel (see below) has to be used. The Trigger in the user panel (see above) has to be set to 0 !!!**
144 -[[~[~[image:url:http://hasfweb.desy.de/pub/Setup/TriggerHowto/mtcatrigger2k.png~|~|alt="mtcatrigger2k.png" width="607" height="458"~]~]>>attach:mtcatrigger2k.png]]
287 +\\
145 145  
146 -here an example defining the bunch pattern for FLASH1 to mask 1
289 +\\
147 147  
148 148  \\
149 149  
150 -[[here is a link to the old VME trigger system>>doc:FLASH.VMETrigger]]
293 +\\
294 +
295 +\\
296 +
297 +\\
298 +
299 +\\