Performance Tests and Control for the TRD-HV

A. Markouizos, A. Petridis, S. Potirakis, M. Tsilis, M. Vassiliou

Athens University

ALICE DCS Workshop CERN March 2006

Requirements of the TRD-HVDS

A Master/Slave HV distribution system will deliver the required voltages to the TRD readout chambers:

Drift HV: 540 ch. ~ -2.5 kV 170μA/ch (max) ΔI ~ 40nA/ch

Anode HV: 540 ch. ~ +1.7 kV 7 μΑ/ch (max) ΔI ~ 2nA/ch

Stability test in the Lab with resistor loads 36 hours of operation for 6 channels

dN/dV distributions for the last 4 hours

after 72 hours of operation

Perfomance test in Heildeberg HV card connected with TRD stack

(18 hours of operation)Voltage in ADC units vs Time

Reference channel with 500Mohm

Embedded Software Status:

Main Structure of Software is completed

Improvements

Optimize the performance

Decrease the response time

Increase Accuracy

Ensure Stability

Module 2Module 1

Crate 4

Module 0

Crate 5

Module 2Module 1Module 0

Crate 3

Module 2Module 1Module 0

Crate 2

Module 2Module 1Module 0

Crate 1

Module 2Module 1Module 0

Module 2Module 1Module 0

Crate 0

Rack 0

Module 2Module 1

Crate 4

Module 0

Crate 5

Module 2Module 1Module 0

Crate 3

Module 2Module 1Module 0

Crate 2

Module 2Module 1Module 0

Crate 1

Module 2Module 1Module 0

Module 2Module 1Module 0

Crate 0

Rack 1

Module 2Module 1Module 0

Crate 0

Concept of connecting the

High Voltage Distribution System to DCS-Bord• Layout of a Rack:

• Layout of a Crate:

• Layout of a Module:

Card 4

Channel 5Channel 4Channel 3Channel 2Channel 1Channel 0

Card 3

Channel 5Channel 4Channel 3Channel 2Channel 1Channel 0

Card 2

Channel 5Channel 4Channel 3Channel 2Channel 1Channel 0

Card 1

Channel 5Channel 4Channel 3Channel 2Channel 1Channel 0

Channel 5Channel 4Channel 3Channel 2Channel 1Channel 0

Card 0 TRD Stack

TRD Supermodule

DCS Board 0 Crate 0

DCS Board 1(Optional)

Module 2(Internal architecture similar to module 0)

Crate 1

(Internal architecture similar to crate 0)

Module 0Card 0

Card 1

Card 2

Card 3

Card 4

Module 1(Internal architecture similar to module 0)

• Architecture of the CAN network inside one rack:

Control Parameters

RAMPING

Error Messages

• Voltage Errors Over Voltage

message: max allowed voltage is exceeded action: voltage is set to the max allowed value

Under Voltage message: min allowed voltage is out of range action: voltage is set to the max allowed value

Limits Error message: set value is out of limits action: limit is set to the default value

• Current Errors (Hardware Error) Over Current

alarm: max allowed current is exceeded or a short-circuit occurred

• Ramping Errors Ramping Rate

message: max allowed rate is exceeded action: rate is set to the max allowed value

Ramping End Value message: end value is out of limits Action: value is set to the max allowed

Limits Error message: set value is out of limits action: limit is set to the default value

Emergency Ramp Down Procedure: This is a special function that ramps down the channel but the rate may be different from the set one. (We suppose that the voltage measurement system is out of order)

Control error on Current measurementActivate the emergency ramp downRamp down and switch off the channel, or ignore.

Due to three (or more) successive comm. errors the channel current Measure is halted. This affects Current Measurement, Over-Current Functions.

ISO ADC communication failed

304

Communication error

in Current measurement System

No action. Channel must be inspected

Warning: Communication error detected in current measurement system. The warning appears for the first and second time this error occurs.

Error in ISO ADC communication detected

303

Control error on Voltage measurement

Activate the emergency ramp down

Emergency Ramp-Down Procedure may be activated. Channel has to be switched off.

Due to three (or more) successive comm. errors the channel voltage control is halted. This affects Voltage Measurement, Over-Voltage, Ramp Functions.

Voltage ADC communication failed

302

Communication error

in Voltage measurement System

No action. Channel must be inspected

Warning: Communication error detected in voltage measurement system. The warning appears for the first and second time this error occurs.

Error in Voltage ADC communication detected

301

PVSS MsgUser Actions

DescriptionTechnical InfoError No

Error Messages (Hardware Errors)

General Communication Error(error #)Card has to be inspected

From this error # the error messages are related with SJA1000 (can controller ) hardware errors. Multiple errors in a short period of time, may be a sign of future loss of the card.

SJA1000 (Can Controller) Errors

308

Channel out of order

No action. Actions should have been taken during the previous events

Due to previous events the control of the channel is halted

Hardware Error on channel

307

Voltage can not be increased to the desired value

Ramp down channel, and then switch it off

Voltage Value has reached the highest hardware possible value. This occurs due to either wrong voltage set or error in voltage control system

Min Voltage DAC Value exceeded

306

Voltage can not be reduced to the desired value

Ramp down channel, and then switch it off

Voltage Value has reached the lowest hardware possible value . This occurs due to either wrong voltage set or error in voltage control system

Max Voltage DAC Value exceeded

305

PVSS MsgUser Actions

DescriptionTechnical InfoError No