DCS is the system responsible for detector switch on and off, including automatic actions that require the switching off of parts of te detector.

Switching the detector ON

The detector can be switch on by sending the Switch_ON command via the FSM. The command is propagated down the FSM tree to all included units, until the HPD columns (Control Unit RICH_DCS_COLUMN). Columns and devices that should not be swiched on can be excluded/disabled. Each DCS column has all the devices and logic to switch on an HPD column. The logic follows the order: LV_HI, LV_LO, L0 boards and Si bias. It also sends a Conf_Limits command to the CU that hold the temperature sensors for the particular column, which should take it to the READY state. If any of the commands in the chain fails, the DCS_COLUMN will go to the ERROR state. More specifically:

  • LV_LO will Switch_ON only after the LV_HI.
  • The L0BoardCtrl device switches the L0 boards one at a time and issues a JTAG reset. The device can go in ERROR if there is no communication via SPECS, or the JTAG reset fails on one or more boards.

An ERROR state is propagated up the FSM tree. If this happens, a Recover command can be send. Ideally, the FSM tree should be expanded in order to see which device is in error before the Recover command.

Panel Description

Where a numerical value is displayed in a panel, double clicking the value will bring up a graph. The contents of the graph depend on whether the value is being archived or not (in which case it will be empty). Keeping the graph open will show all value changes from that point on, however, the values are lost when the graph is closed if they are not archived.

The backround colour of the value shows the alert state, according to the framework conventions:

  • White: no associated alarm.
  • Green: OK.
  • Yellow: Warning.
  • Orange: Error.
  • Red: Fatal.

Keeping the mouse over the value for a small period of time will display the time when the value was last updated. This is useful if there is suspicion that the value may not be correct.

DCS Top Level (detector level)

The panel at the top level shows the state of the SPECS servers for the two detector sides. The computer where the server should be running is shown and the background colour shoes the state:
  • Green: Server is running.
  • Red: Server is not running. It needs to be started before the detector can be switched on.
  • Yellow: Server state unknown.

There is also a button for sending the "Conf_Limits" command to all the tempearature objects in order to read the pre-configured alarm limits and movefrom the NOT_READY state to READY or READY_WARN.

Half detector (side A/C or U/D)

This panel has four buttons that allow to enable/disable all the Si bias or L0 borad control devices. For example if the detector requires to be switched off and on while keeping the Si bias ON, all Si Bias devices can be disabled before the Switch_OFF command, so they will stay ON.

These buttons can only be operated when the user has control of the CU.

HPD Column

The HPD column panel shows the voltage and current of the two Maraton (LV) and the CAEN (Si bias) channel.

LV and SiBias Channels

The panels of these channels show the status of the particular channel in more detail. Clicking on the "Details" button brings a panel that allows the operation of the channel. Operating the LV channels in this mode should be done only in emergencies as the order they switch on is very important. Switching them on in the wrong order can blow a fuse which will require hardware intervention.

If the Si bias channel stays in the OFF state it is probably externaly disabled. Right clicking on the device in the HPD column panel may give more information.

L0 Board Control

This Panel allows the operation (switch on/off) of the L0 boards via SPECS. The L0 boards are switched on via voltage regulators that are controlled via the OutLSB and OutMSB registers on the SPECS mezzanine. These registers are by default set as input, and they can be configured as output by changing the values of the ConfOutLSB and ConfOutMSB registers from 0 to 1 (all bits). So, when a column is OFF, the values of all 4 registers is 1 for every bit. Switching boards on means writing 0 to specific bits in the two Out registers. Pressing the "Read Status" button will read these 4 16 bit registers (displayed as two 32 bit ones) and will possibly update the state of the device. If the background is green, the registers were read without error. If the background is yellow, an error occured so the values of the regisers are not known.

The "Local control" check box allows the opeartion of the device via the panel. It is available only if the device is in the states OFF, NOT_READY and READY.

The "L0 Boards" check box shows which boards will be switched on when the Switch_ON command is send. The values can be changed by the operator only when the device is in the OFF state. When the boards that are ON are the same as the boards that are checked in this check box are the same, the device will go to the READY state. If they are not the same, the device will be in the NOT_READY state.

The coloured buttons control the state of the L0 boards. Pressing them will switch a board ON or OFF. When a board is switched on, a JTAG reset is sent. If this fails, the boards is switched off and the device will go in error. Sending the "Recover" command will remove the error.

If the desired state of the column is different from the default, the "Go to READY" button can be used to set the boards that were expected to be on to be the same as the boards that are on at the time.

If the communication with the SPECS mezzanine fails when a command is given the device will go in error. Communication can be checked using the "Reda Status" button. A SPECS soft reset can also be sent using the "Reset Master" button.

Column Temperature

The Column Temperature panel shows the temperature sensors on the LV regulators. Sensors can be enabled or disabled, their value is displayed and up to eight can be shown in the graph together using the check boxes. A valid range for a temperature is from 0 to 1000 degrees C.

Single Temperature Sensor

This is the FwAi (framework analogue input) operate panel. It shows the alarms defined for the temperature and allows to acknowledge an alarm.

When something goes wrong (ERROR)

When something goes wrong, the relevamt device goes in the ERROR state, and the ERROR is propagated up the FSM tree. Before any action is taken, the cause of the problem should be identified. There is no point in sending a Recover command if a temperature is too high. The device that is in ERROR can be identified by following the ERROR in the FSM tree.

Under cetrain conditions the FSM will take automatic actions to stop possible damage to the harware and put the system in a safe state, EMERGENCY_OFF. Again the problem should be identified before the emergency is cleared.

To be written (Antonis).

Detector Monitoring

The collection of information for the monitoring of the detector is done either using ELMBs (project R2DCS2) to readout out various sensors, like temperature, humidity and pressure, or geting information from the power supplies (project R2DCS1) about voltage and current.

The sensor information that should be used for actions is integrated in the FSM, including the state of the ELMBs.

Information Panels

In the folder info in the rich froup directory (G:\rich\Info or /group/rich/Info) there are a number of panel that only dispaly information, without the possibility of sending actions (part from the Light Leak panel, which can operate the ELMB in D3). Actions are always send using the FSM panels.

Double clicking a displayed value will bring up a plot with archived inromation. The information displayed depends on the archiving settings (if any).


The Rich Overview panel dispalys information about the state of the HPD columns; the voltage and current of the two LV channels, the Si bias channel, the UP and DOWN 20 kV monitored voltages and the state of the temperature object.


This panel shows the value of two temperature sensors, humidity and cooling pressure for each HPD enclosure (A and C side). The dew point is also calculated to show if there is danger of condensation.


The light leak panel shows the status of the light leak detector. The "Light Level" shows a level proportional to the amount of light in the HPD enclosure. It turns orange above a certain limit and when it turns red, the interlock has been activated. The "Power On Level" shows whether there is some noise from the PMs to indicate whether they are on. Below a certain level the interlock is activated and the display turns red.

There is also a display of the ELMB state. Operational is the normal state. Disconnected means the ELMB is physically disconnected or has no power or has crashed. Physical operation is requited to get it to work again. Stopped means the ELMB need to be started. This is possible by double clicking the state display. Unless the state is operational the dispalyed values cannot be trusted.


Temperatures and humidity inside the Rich2 radiator volume. It's possible to plot up to 8 temperatures in a single window.

[Normal operation][Alarm handling and Emergency recovery].

To be written (Antonis).

-- AntonisPapanestis - 20 Nov 2007

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Topic revision: r1 - 2007-11-20 - AntonisPapanestis
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