ECS Questionnaire

Questions on controls for each subdetector and activity

Forward

Currently work is under way on a User Requirement Document for the Detector Control System [DCS], or Slow Controls as it used to be called. Pere Mato (coordinator), Andre Augustinus and Wolfgang Tejessy are working on this for LHCb. We need input from subdetectors and also from activities not connected (solely) to any subdetector, such as gas, magnet, DAQ run control, safety,... And for that we must put together a list of contact persons to cover all activities that will need some computer control or monitoring. Do help us to compile a complete list of contact persons. If you propose yourself, please answer the following questions, else make sure that the person you propose does it with the necessary input from you. Answers to wolfgang.tejessy@cern.ch.

Problem definition

For the evaluation of our needs to monitor and control the LHCb and its parts, we would like to collect information on what sort of requirements you have. While it is surely too early and therefore of limited use to try and come up with fixed tables of numbers for the common monitoring elements, it would be of interest to know already now if you have special control intentions that are specific to your application. We would like to know about requirements above the more or less standard things we have gotten accustomed to from LEP-type experiments, such as switching various crates ON and OFF, controlling standard high voltage supplies, reading environmental parameters (temperature probes, pressures sensors, etc.) and various low voltages or currents. Are you for instance thinking of using the DCS to actively align some mechanics or use it to configure front-end electronics, load timing information, thresholds, calibration information, etc.?

Questions

In this connection we have compiled a list of questions, which is in no way exhaustive, but should give a feeling for what we would like to get information on. · Do you foresee any closed-loop control, if yes at which point and rate would the DCS intervene (e.g. in the loop itself or would there be a separate control loop that the DCS only "sees" from the outside?)

• Is any mechanical alignment procedure via DCS under discussion?
• Is the use any Programmable Logic Controller [PLC] foreseen?
• If the DCS front-ends are not based on VME, will this cause a problem?
• Do you foresee a dedicated control subsystem that you buy from industry as an integral part of an equipment and for which you require an interface to the DCS?
• If you plan purchasing such a control subsystem, give details about it (platform, buses, ...)
• Are you already committed to devices with special interfaces (GPIB, RS232, proprietary buses, etc.)
• Will you use the DCS for high-speed or substantial-volume data acquisition (more than the standard gathering of environment parameters, e.g. other than various ambient temperatures, pressures, states, ...)
• Do you need high-precision data, e.g. analog readings above 12bit resolution or with long integration time or multiple sampling with smoothing, etc.?
• For which type of parameters do you think that your application will have above-average needs?
• What type of data and how much do you wish to make available to the off-line reconstruction and analysis?
• Can you envisage any alarms that you would wish to see in this output stream?
• Do you require archiving capabilities in the DCS for substantial volumes of data (not just the odd environmental parameters)?
• Do you need large or fast switching capabilities (other than switching ON/OFF your crates, some modules, etc.)
• Do you envisage the need of appreciable computing power in the DCS?
• If already available, first indication of number and types of input and of output parameters you wish to handle would be of help.

To conclude: With the above questions in mind, it would be nice to get a general description of the major usage that you foresee of the DCS for your application. Please send this description to wolfgang.tejessy@cern.ch. Thanks.

Pere & Wolfgang

Dec. 2, 1997