lv and hv status of the rpc system rpc detector and trigger group

LV and HV status of the RPC system

RPC detector and trigger group

Pigi Paolucci - CMS LV review 2

Equipment type Total installed spare % of spare

SY1527 SY1527 5 4 1 25,0%

A3485 A3485 5 3 2 66,7%

A3512N HV 127 116 11 9,5%

A1676 BC A1676 20 17 3 17,6%

EASY3000S CRATE 40 38 2 5,3%

EASY3000 CRATE 44 39 5 12,8%

A3000FB FAN 27 23 4 17,4%

A3486S_380 MAO AC/DC 12 10 2 20,0%

A3009 LV DC/DC 105 96 9 9,4%

A3801A Temperature AC/DC 17 14 3 21,4%RPC HV distributor Barrel HV Distribution Box 37 35 2 5,7%A3486S_230 Endcap MAO AC/DC 13 12 1 8,3%RPC HV distributor Endcap HV Distribution Box 24 24 0 0,0%

A3016 LV DC/DC 68 64 4 6,3%

RPC LinkBoardBox LBB 105 96 9 9,4%

RPC MasterBoard MLB 351 300 49 16,3%

RPC SlaveBoard SLB 574 500 70 14,0%

RPC ControlBoard CB 124 120 4 3,3%

RPC LB FrontPanel LB FP 125 120 5 4,2%

RPC OptoBox OB 14 10 4 40,0%

7/6/10


Electronic status

HV: 694/696 99%LBB: 384/384 100%LV: 1050/1052 99%T: 401/401 100%

• LV detector system is working smoothly.• HV system:

– 3 boards are under investigation at CAEN– Few coaxial connectors replaced – well know insulator

• Problem appears very often after SY1527 kill/power cut• 2nd generation of insulators (factory) are, until now, stable• 3nd generation of insulators (custom) are under design in Napoli

• Manpower is ok (3 experts at CERN)

7/6/10


Low Voltage Link Board status

• After many failures in the link board system the RPC-Trigger community decided to investigate all the possible causes analyzing not only the LB system but also the LV system:

• A3016 boards• MAO• LV and MAO power cut and power cycle• Power off and on of the link box• CAEN firmware

7/6/10

A3016 behavior cutting the MAO 3Phase


LV link board Schema

1. MAO 48 service from BC– Output current = 15-18 A

2. EASY 3000 – Joint 48 Power & Service

3. Output power from A3016:– 2.5 Volts / 5.0 Amp– 3.5 Volts / 10.0 Amp

MAO

SY1527

48 service

3-phase

EASYA3016

48 service48 power

Link Box7/6/10


What powering OFF the MAO in the proper ways ?

• Powering OFF the MAO via SY1527 or using the interlock placed on the front

OK

7/6/10


What powering OFF the EASY in a “bad” way ?

• Powering OFF the EASY 3000 crate removing the power or service connector from the back

OK

7/6/10


What cutting the MAO 3-phase ?

• Shutting-down the MAO cutting 3-phase

•oscillation does not depend from the MAO load (from 4 A to 18 A)

•sometimes 2 oscillations in few msec

•oscillation disappear separating the 48 power from the 48 service

•No other ways to reproduce it

NOT OK7/6/10


What happen cutting MAO 3-phase ?• MAO goes OFF in 2 steps: from 48 to 22 V and a from 22 to 0 V • The A3016 channels go off when MAO voltage is around 22 V and

this takes about 250-300 msec (fixed load on the MAO)• Around 22 V the boards begin to work not properly (Vcc goes from

12 V to 6 V) and generates oscillations on Vout.

7/6/10

Vmao = 22 V

Vcc = 12 V

6 V

7/6/10 10Pigi Paolucci - INFN

Mao behavior during 3Phase glitch


T0 T1

At T0:• Turn off the 3-phase switch• MAO starts ramping down with a “dummy load” - NO status changing • After a while, it gives UNV status, but the channel keeps status ON.

At T1:• MAO ramps down with different slope (real load)

At T2:• MAO swiched ON (600 ms from T0).

Switching OFF-ON in <1sec, no IntFail status is generated by the MAO and the channel goes back to the 48V without any alarm acknowledge.

T2

Scope output

MAO

A3016

40 V

7/6/10


What we have done !Already implemented Solutions:

• Introducing a big capacitor (33 mF) between the service and power line of the EASY

• Improve the A3016 firmware • Modify the MAO firmware

Long Term Solutions:1. Designing a protection on the Link Box LV lines

(see tomorrow meeting) 2. Separating the 48 service and power of the

EASY ?7/6/10

OK

Under test now

Under test now


A3016 firmware requirements

• Couple of channels in tracking mode (ON/OFF/Trip at same time and with one command).– delay between the 2 channels must be less than 1 msec

• Ramping up in stepping mode:– overshoot first steps < 10% of the setting voltage– overshoot of the last step must be < setting voltage– voltage must be always < setting voltage (no overshoot above max value)– Over-voltages are very dangerous for the LB.

– no under-voltage dips are allowed after VCC2.5 gets above 2.0 V– no under-voltage dips are allowed after VCC3.3 gets above 1.2 V– total time to reach the setting voltages (3.5 V and 2.5 V) should be less than

60 msec

7/6/10


MAO firmware requirements

• The MAO behavior is case of glitch on the 3-phase line is potentially dangerous for the LV system.

• Turn OFF the MAO when the Vmon < 43-40 Volts in about 100 msec and require an acknowledge afterwards to bring the channel back to ON.– In 100 msec firmware measures the voltage 5 times,

should be enough.– After 100 msec the MAO voltage is around 35-38 V

and it is enough to shut-down properly the A3016.7/6/10

Pigi Paolucci - CMS LV review 167/6/10

MAO

Vcc

Vout

New MAO firmware

old MAO firmware

Oscillations on both Vccand Vout

200 msecOFF – 38V

43V

New MOA firmware


Rumping up - new A3016 firmware

50 msec

80 msec

2.5 V

3.5 V

No overshot over the max voltage


Overshot - new A3016 firmware

Overshot < 10-15% voltage set


Channels delay- new A3016 firmware

2 msec

Delay stable and < 2 msec (depends on the charge)


Results with C and diode

power

service

1.5 sec

7/6/10


Results with C and diode

2.5 V

48 VNo spikes or oscillations

600 msec

7/6/10


Conclusions• Running systems is very stable• Spares are under control (> 5%)

• Many improvements done on the trigger LV system to assure a more stable and safe behaviors of the Link System

• Hardware protection of the Link Box is under test (Warsaw group)

7/6/10

lv and hv status of the rpc system rpc detector and trigger group

Documents

mao load

lv dcdc1059699

lv dcdc686446

trigger lv system

lv detector system

mao voltage

mao ramps

mao power cut