ALICE DCS Workshop CERN March 2006

1. Performance Tests and Control for the TRD-HVA. Markouizos, A. Petridis, S. Potirakis, M. Tsilis, M. VassiliouAthens University ALICE DCS Workshop CERN March 2006

2. 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

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

5. dN/dV distributions for the last 4 hours after 72 hours of operation

6. Perfomance test in Heildeberg HV card connected with TRD stack (18 hours of operation) Voltage in ADC units vs Time Reference channel with 500Mohm

7. Embedded Software Status: • Main Structure of Software is completed • Improvements • Optimize the performance • Decrease the response time • Increase Accuracy • Ensure Stability

8. Concept of connecting the High Voltage Distribution System to DCS-Bord Rack 0 Rack 1 Crate 0 Crate 0 Module 0 Module 1 Module 2 Module 0 Module 1 Module 2 Crate 1 Crate 1 Module 0 Module 1 Module 2 Module 0 Module 1 Module 2 Crate 2 Crate 2 Module 0 Module 1 Module 2 Module 0 Module 1 Module 2 Crate 3 Crate 3 Module 0 Module 1 Module 2 Module 0 Module 1 Module 2 Crate 4 Crate 4 Module 0 Module 1 Module 2 Module 0 Module 1 Module 2 Crate 5 Crate 5 Module 0 Module 1 Module 2 Module 0 Module 1 Module 2 Crate 0 Module 0 Module 1 Module 2 Card 0 Channel 0 Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 Card 1 Channel 0 Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 Card 2 Channel 0 Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 Card 3 Channel 0 Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 Card 4 Channel 0 Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 • Layout of a Rack: • Layout of a Crate: • Layout of a Module:  TRD Stack  TRD Supermodule

9. Architecture of the CAN network inside one rack: DCS Board 0 Crate 0 Module 0 Card 0 Card 1 Card 2 Card 3 Card 4 Module 1 (Internal architecture similar to module 0) Module 2 (Internal architecture similar to module 0) Crate 1 (Internal architecture similar to crate 0) DCS Board 1 (Optional)

10. Control Parameters

14. RAMPING

15. 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

16. Error Messages (Hardware Errors) Error No PVSS Msg User Actions Technical Info Description 301 Error in Voltage ADC communication detected Warning: Communication error detected in voltage measurement system. The warning appears for the first and second time this error occurs. Communication error in Voltage measurement System No action. Channel must be inspected Control error on Voltage measurement Activate the emergency ramp down Emergency Ramp-Down Procedure may be activated. Channel has to be switched off. 302 Voltage ADC communication failed Due to three (or more) successive comm. errors the channel voltage control is halted. This affects Voltage Measurement, Over-Voltage, Ramp Functions. 303 Error in ISO ADC communication detected Warning: Communication error detected in current measurement system. The warning appears for the first and second time this error occurs. Communication error in Current measurement System No action. Channel must be inspected Control error on Current measurement Activate the emergency ramp down Ramp down and switch off the channel, or ignore. 304 ISO ADC communication failed Due to three (or more) successive comm. errors the channel current Measure is halted. This affects Current Measurement, Over-Current Functions. 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)

17. Error No Technical Info Description PVSS Msg User Actions 305 Max Voltage DAC Value exceeded Voltage Value has reached the lowest hardware possible value . This occurs due to either wrong voltage set or error in voltage control system Voltage can not be reduced to the desired value Ramp down channel, and then switch it off 306 Min Voltage DAC Value exceeded Voltage Value has reached the highesthardware possible value. This occurs due to either wrong voltage set or error in voltage control system Voltage can not be increased to the desired value Ramp down channel, and then switch it off 307 Hardware Error on channel Due to previous events the control of the channel is halted Channel out of order No action. Actions should have been taken during the previous events 308 SJA1000 (Can Controller) Errors 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. General Communication Error (error #) Card has to be inspected