Changes for page Trigger Howto

Last modified by sndueste on 2023/07/07 11:28
From version 19.1
edited by sndueste
on 2020/01/23 09:29
Change comment: There is no comment for this version
To version 6.1
edited by sndueste
on 2019/09/17 13:36
Change comment: There is no comment for this version

Summary

Details

Page properties
Content
... ... @@ -2,41 +2,19 @@
2 2  
3 3  {{toc/}}
4 4  
5 -= Introduction (user panel)
6 - =
5 += Introduction =
7 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 in [[x2Timer manual>>attach:x2Timer.pdf]] ([[Design Paper>>url:http://ttfinfo2.desy.de/doocs/Timing/CDRv2.2short.pdf||shape="rect"]]).
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]].
9 9  
10 -In short:
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.
11 11  
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
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]]
22 22  
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)
24 24  
25 -
26 26  \\
27 27  
28 -\\
16 += different trigger events (starting points) =
29 29  
30 -\\
31 -
32 -\\
33 -
34 -\\
35 -
36 -\\
37 -
38 -= Different trigger events (starting points) =
39 -
40 40  one can configure each channel for an individual trigger event
41 41  
42 42  **FLASH1**
... ... @@ -105,8 +105,6 @@
105 105  
106 106  \\
107 107  
108 -\\
109 -
110 110  = Expert panels =
111 111  
112 112  \\
... ... @@ -113,11 +113,11 @@
113 113  
114 114  [[image:attach:image2019-9-17_13-10-56.png||height="250"]] [[image:attach:image2019-9-17_13-8-46.png||height="400"]]
115 115  
116 -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)
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)
117 117  
118 118  \\
119 119  
120 -For each trigger channel there is in addition an **"Expert panel"** to set the properties of THIS channel
96 +For each trigger channel there is in addition a expert panel to set the properties of THIS channel
121 121  
122 122  [[image:attach:image2019-9-17_13-14-52.png||height="250"]] [[image:attach:image2019-9-17_13-15-38.png||width="550"]]
123 123  
... ... @@ -125,26 +125,23 @@
125 125  
126 126  \\
127 127  
128 -= Set a constant frequency to a channel =
104 +\\
129 129  
130 -=
106 += Set a constant frequency to a channel
131 131  [[image:attach:image2019-9-17_13-18-9.png||height="250"]][[image:attach:image2019-9-17_13-18-37.png||height="149"]] =
132 132  
133 133  \\
134 134  
135 -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 !!**
111 +\\
136 136  
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 !!**
114 +
137 137  Since our main FEL frequency is 100.31 MHz the dividers are not straight forward:
138 138  
139 -[[image:attach:image2019-9-17_14-22-29.png||width="450" align="right"]]
140 -
141 -\\
142 -
143 -(% class="wrapped" %)
144 144  |=(((
145 145  Clock frequency
146 146  )))|=(((
147 -Divider to be set
120 +Devider to be set
148 148  )))
149 149  |(((
150 150  "1 MHz" (1000.31 kHz)
... ... @@ -152,141 +152,26 @@
152 152  53
153 153  )))
154 154  |(((
155 -"500 kHz" (501.5 kHz)
128 +\\
156 156  )))|(((
157 -107
158 -)))
159 -|(((
160 -"250 kHz" (250.8 kHz)
161 -)))|(((
162 -215
163 -)))
164 -|(% colspan="1" %)(((
165 -"200 kHz" (200.6 kHz)
166 -)))|(% colspan="1" %)(((
167 -269
168 -)))
169 -|(% colspan="1" %)(((
170 -"100 kHz" (100.3 kHz)
171 -)))|(% colspan="1" %)(((
172 -539
173 -)))
174 -
175 175  \\
176 -
177 -== General FLASH frequencies: ==
178 -
179 -\\
180 -
181 -(% class="relative-table wrapped" style="width: 19.422%;" %)
182 -|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
183 -(% style="color: rgb(0,0,0);" title="" %)**Name          
184 -**
185 -)))|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
186 -(% style="color: rgb(0,0,0);" title="" %)**Frequency                
187 -**
188 -)))|(% class="highlight-grey" title="Hintergrundfarbe : Grau" data-highlight-colour="grey" %)(((
189 -(% style="color: rgb(0,0,0);" title="" %)**Divider**
190 190  )))
191 191  |(((
192 -1.3 GHz
133 +\\
193 193  )))|(((
194 -1300.000000 MHz
195 -)))|(((
196 196  \\
197 197  )))
198 -|(((
199 -108 MHz
200 -)))|(((
201 -108.333333 MHz
202 -)))|(((
203 -12
204 -)))
205 -|(((
206 -9 MHz
207 -)))|(((
208 -9.02777777 MHz
209 -)))|(((
210 -144
211 -)))
212 -|(((
213 -4.5 MHz
214 -)))|(((
215 -4.513888 MHz
216 -)))|(((
217 -288
218 -)))
219 -|(((
220 -1 MHz
221 -)))|(((
222 -1.003086 MHz
223 -)))|(((
224 -1296
225 -)))
226 226  
227 227  \\
228 228  
229 -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.
230 -
231 -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 ...
232 -
233 -This results in a continuous train of pulses with the set trigger width.
234 -
235 -= Creating an (own) burst trigger =
236 -
237 -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,
238 -
239 -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.
240 -
241 -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).
242 -
243 -**To get from the clock to the burst trigger** one has to:
244 -
245 -* set the  "2nd source select" to the gate trigger ( here FRONT.TRG2) - this defines a second source to considder for the trigger output.
246 -* 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.
247 -
248 248  \\
249 249  
250 -[[image:attach:image2019-9-17_14-35-5.png||height="250"]] [[image:attach:image2019-9-17_14-34-38.png||width="400"]]
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]]
251 251  
252 -\\
146 +here an example defining the bunch pattern for FLASH1 to mask 1
253 253  
254 254  \\
255 255  
256 -= Real bunch trigger  - get a trigger for each FEL pulse =
257 -
258 -\\
259 -
260 -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.
261 -
262 -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)
263 -
264 -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.
265 -
266 -[[~[~[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"]]
267 -
268 -\\
269 -
270 -In the expert panel one can now choose the configured "Bunch Pattern" as "Input source select"
271 -
272 -**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 ...**
273 -
274 -\\
275 -
276 -[[image:attach:image2019-9-17_15-4-47.png||height="250"]][[image:attach:image2019-9-17_14-52-40.png||height="250"]]
277 -
278 -\\
279 -
280 -\\
281 -
282 -\\
283 -
284 -\\
285 -
286 -\\
287 -
288 -\\
289 -
290 -\\
291 -
292 -\\
150 +[[here is a link to the old VME trigger system>>doc:FLASH.VMETrigger]]