GOD, ORB (Orbit)

Document status	FINAL
Document owner	Alessandro Stecchi
Designer	Alessandro Stecchi
Developers	Alessandro Stecchi
QA	Alessandro Stecchi

Description

The DAFNE orbit is acquired by 4 front-end DEVILs (364, 365, 366, 367) and post processed by the DEVIL204.
The basic elements created by the 4 front-end DEVILs are:

```
ORBRAK063 (364)
```
```
ORBRAK071 (365)
```
```
ORBRAK070 (366)
```
```
ORBRAK066 (367)
```

and the final element created by the DEVIL204 is:

```
GOD**001
```

The DEVIL204, besides the two conventional GOD**001_STA and GOD**001_DYN forks, builds also a circular buffer of data (containing the actual real-time X and Y orbit projections) accessible in the VME address space. To have this data also available on non-VME processors, a dedicated proxy constantly reads the GOD**001_STA and GOD**001_DYN forks, as well as the circular buffer from VME, and transfers them to memcached.

Source

[DEVIL364, 365, 366, 367] > [DEVIL204] > [Orbit_Proxy]

Requirements

Key name	Source	Write freq. [Hz]	Data size [byte]	Throughput [kbyte/s]	Fomat	Notes
GOD**001_STA	Orbit_Proxy	-	2624	-	typeDef	LV cluster [flattened to str]
GOD**001_DYN	Orbit_Proxy	10	46	0.45	typeDef	LV cluster [flattened to str]
ORBP*DAT_BUF	Orbit_Proxy	10	1024	20	2D [DBL]	2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str]
ORBE*DAT_BUF	Orbit_Proxy	10	1024	20	2D [DBL]	2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str]
ORBP*AVG_BUF	Orbit_Proxy	10	1024	20	2D [DBL]	2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str]
ORBE*AVG_BUF	Orbit_Proxy	10	1024	20	2D [DBL]	2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str]
ORBP*VAR_BUF	Orbit_Proxy	10	1024	20	2D [DBL]	2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str]
ORBE*VAR_BUF	Orbit_Proxy	10	1024	20	2D [DBL]	2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str]

Key name	Source	Write freq. [Hz]	Data size [byte]	Throughput [kbyte/s]	Fomat	Notes
GOD**002_STA	DEVIL704	-	2624	-	typeDef	LV cluster [flattened to str]
GOD**002_DYN	DEVIL704	5.5	46	0.25	typeDef	LV cluster [flattened to str]
ORB-E-64_INFO ORB-P-64_INFO	DEVIL704	-	~2500	-	Json document	Static description of the orbit with name, ascissa and index of each element. name: name of the BPM; s (curvilinear abscissa), position along the ring [m]; i: index of the component corresponding to the element "name" in the 64-DBL array. Should index be equal "-1", that element must be ignored. This happens when: that BPM has been excluded (by a mask); there is no BPM connected to that channel. In that case "name" is "BPMDUMMY" and the curvilinear abscissa "s" is 0) [ { "name":"BPBEL101", "s":2.531, "i":0 }, { "name":"BPBEL102", "s":6.205, "i":1 }, ... { "name":"BPBEL209", “s":96.228, "i":59 } ]
ORBE*NOD_BUF ORB-E64-MEAN_BUF	DEVIL704	5.5	1024	5.5		Electrons: average(N) of the orbit (hor + ver) 2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str] 64-components array with moving average calculated on the last N samples.
ORBP*NOD_BUF	DEVIL704	5.5	1024	5.5		Positrons: average(N) of the orbit (hor + ver) 2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str] 64-components array with moving average calculated on the last N samples.
ORBE*STD_BUF	DEVIL704	5.5	1024	5.5		Electrons: Std. Dev. of the average(N) orbit (hor + ver) 2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str] 64-components array with standard deviation calculated on the last N samples.
ORBP*STD_BUF	DEVIL704	5.5	1024	5.5		Positrons: Std. Dev. of the average(N) orbit (hor + ver) 2 rows of 64 DBL (row 0: hor, row 1: ver) [flattened to str] 64-components array with standard deviation calculated on the last N samples.
ORBE*USR_BUF ORB-E-MEAN8_BUF	DEVIL704	5.5	~700	3.9		Electrons: average(8) of the orbit ready for users (hor + ver) 2 rows of m DBL (row 0: hor, row 1: ver) [flattened to str] m-components array with moving average calculated on the last 8 samples. The number of components "m" (typ. 44) depends on the current BPMs setup and the hardware and user masks. The array is ready for viewing.
ORBP*USR_BUF	DEVIL704	5.5	~700	3.9		Positrons: average(8) of the orbit ready for users (hor + ver) 2 rows of m DBL (row 0: hor, row 1: ver) [flattened to str] m-components array with moving average calculated on the last 8 samples. The number of components "m" (typ. 44) depends on the current BPMs setup and the hardware and user masks. The array is ready for viewing.

Total throughput

kbyte/s	Mbit/s
~30	~0.23

Keys usage

Example of LabVIEW code to use at level 1 to unflatten and extract the two projections of the orbit:

Example of 2D array (3 columns, 2 rows)

< #rows >|< #cols >|   a00   |    a01  |   a02   |   a10   |   a11   |   a12   
---------|---------|---------|---------|---------|---------|---------|---------
0000 0002 0000 0003 0000 0000 0000 0001 0000 0002 0000 000A 0000 000B 0000 000C

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Description

Requirements

Total throughput

Keys usage