1. RPC Detector Control System
Pierluigi Paolucci - I.N.F.N. of Naples

2. Pigi Paolucci, I.N.F.N. of Naples
Where we are
I.N.F.N. Naples
HV-LV (naples):
hardware prototype #0 under test since apr 02 (mag, rad & stress)
software  PVSS prototype for SY (dec 02)
Environmental:
hardware
software 
Front-end:
Gas, cooling and ventilation:
rack and crate:
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

3. What we want to monitor:
Detector Control System I
I.N.F.N. Naples
What we want to monitor:
HV and LV values  OPC server  30 Kbytes;
FEB disc. Thresholds I2C  100 Kbytes;
FEB pulse width I2C  100 Kbytes;
FEB temperature I2C  25 Kbytes;
Single Counting Rate I2C  to be calculated;
Cooling system  ?  ? ;
Gas system  ?  ? ;
Ambient parameters  ?  ? .
All data have to be logged into the Databases
We will use different monitor rates to minimize the DB data rate
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

4. Detector Control System II
I.N.F.N. Naples
Which parameters we have to load from the configuration DB for the different run-types (high/low background, calibration, RPC plateaux….):
HV/LV setpoints
FEB disc. thresholds;
FEB pulse width;
Status ON/OFF…
Voltage V0/V1set
Current I0/I1set
Rump-up Rup
Rump-down Rdown
Trip time Trip
At least 10 different HV-LV configurations
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

5. Pigi Paolucci, I.N.F.N. of Naples
HV Barrel
I.N.F.N. Naples
The barrel system consists of:
wheel 1 2 3 4 5
TOT
gaps
408
2040
hv ch.
204
1020
remote board 48
240
crates 8 40
racks m
1020 hv channels  1 SY1527
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

6. Pigi Paolucci, I.N.F.N. of Naples
HV Endcap
I.N.F.N. Naples
Each endcap system consists of:
station
RE1
RE2
RE3
RE4
TOT
chambers
108 90
468
hv ch.
216
180
756
RDB 54 45
189
crates 6 5 21
racks m 2 8
756 hv ch.  1 SY1527
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

7. Pigi Paolucci, I.N.F.N. of Naples
LV system description
I.N.F.N. Naples
BARREL
26 ch/sector * 12 sectors * 5 wheels = 1560 LV ch.
3 RDBs/sector  36 RDBs/wheel  180 RDBs.
ENDCAP
About 1200 LV ch corresponding to 100 RDBs
The LV Barrel system needs less Remote Board than the HV system and then 1 SY1527 is OK
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

8. Total number of data to monitor for HV/LV
SYSTEM
BRL ch.
EDC ch.
Values
TOTAL HV
1020
1512 6
15192 LV
1560
1200 4
11040
For the Barrel we need 240 Remote Boards placed in 40 HV distribution crates.
For the Endcap we need about 380 RBs but the number depend on the geographical distribution of the HV distrib. crates (under discussion)
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

9. 19536 Threshold + 19536 width + 7224 temp.
FEB monitor/control data I
I.N.F.N. Naples
BARREL:
78 FEB/sector * 12 sectors * 5 wheels = 4680 FEBs
9360 Threshold width temp.
13 I2C lines/sector = 780 I2C lines
ENDCAP:
2544 FEBs (4 chips)  336 I2C lines
10176 Threshold width temp.
spare
TOTAL number of FEB variables to monitor:
19536 Threshold width temp.
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

10. spare FEB monitor/control data II
I.N.F.N. Naples
Barrel FEBs are equipped with 2 front-end chips (8 strips each) and 1 temperature sensor corresponding to the following parameters to monitor and control:
2 threshold values (hardware defaults of 200 mV);
2 width values (hardware defaults of 100 ns);
1 temperature value.
How many operations/bytes do we need to read/write this parameters with the I2C??
Read width/thresh.  2 write + 1 read  5 bytes
Read temperature  2 write + 1 read  5 bytes
Write width/thresh.  3 write  5 bytes
spare
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

11. spare FEB monitor/control data III 117 Kbytes 94 Kbytes
I.N.F.N. Naples
To monitor all the barrel FEB parameters we need:
46800 bytes (width)
46800 bytes (thresh.)
23400 bytes (temp.)
To write a “new” width and/or threshold we need:
46800 bytes (thresh.);
How often do we need to monitor them ?
example 
How often do we need to modify them ?
High background
To reduce the dead time
117 Kbytes
94 Kbytes
50 KB/h  1.2 MB/day
spare
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

12. Pigi Paolucci, I.N.F.N. of Naples
More DCS items
I.N.F.N. Naples
Gas system:
The Gas system group will provide us also the slow control system to integrate in our DCS.
Cooling:
The slow control for the cooling will be developed with the DT people or by a CERN group.
Ambient:
The ambient temperature and pressure will be monitored using the DT system.
We are discussing about the humidity monitoring.
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

13. Single Rate and occupancy I
I.N.F.N. Naples
The Single Rate and the occupancy are very useful data to monitor:
the performances/aging of the RPC detectors
They are also very sensible to the background conditions, to the HV working point, to the Gas mixture and to the FEB threshold and so can be used as an indirect monitor of these variables/systems.
After some discussion we would like to propose to monitor them per chip (8 strips) with a refresh rate less than 30 sec in order to able to react in a short time
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples

14. Single Rate and occupancy II
I.N.F.N. Naples
The histograms parameter and time window should be programmable through the I2C line.
The total number of channels to monitor are in the barrel and about in the endcap.
Now the questions are:
How many bytes do we need per each histograms ?
How many CAN-bus lines do we need ?
How many bytes do we need to store in the DB ?
In which cases we want to write them ?
Which is our loading rate into the DB ?
15/01/2019
Pigi Paolucci, I.N.F.N. of Naples