White Light Source

Limitations

  1. The halogen light source HL-2000-HP-232R sends no acknowledgement after reception of a command. Therefore, the programmer is never sure if the command was accepted and executed successfully by the device.
  2. The device lacks a mechanism to query the lamp status. The programmer is unable to tell for sure if the lamp is on or off.
  3. In order to ensure that the lamp is turned off, the device should be powered off. It is insufficient to send a command to the device for turning the lamp off (CO). The reason for this is the lack of acknowledgement for commands. It is possible that the device is unable to turn off the lamp. Futhermore, the command CO could be lost if the communication with the device goes over an ethernet-to-serial server and the device is quickly deattached and reattached from this server.
  4. Ocean Optics engineer Patrick Zeller wrote in an e-mail that "there is some uncertainty in position regulation. So I allow a deviation of +-2 steps in position. [...] Sometimes small movements are not carried out. This is caused by the above mentioned uncertainty in positioning. This means movements of less than ~3 +steps may be carried out or not. If you need to do single steps then I would suggest to move back 10 steps and then go to the desired position."
  5. Often, the under-voltage error bit is set. This happens even with the official power supply. Ocean Optics engineer Patrick Zeller: I'm not sure why the Undervoltage bit is set. There could be a problem with the supplied voltage breaking down for short periods, but that's only a guess.

Communication Settings

The following serial port settings are required:

Baud rate 9600
Data bits 8
Parity None
Stop bits 1
Flow control None

Screen-shots

white_light_source_engineering_gui.png

Property Tree Configuration

A complete example of a property tree configuration file can be in the repository.

Mandatory Properties

The basda device for the white light source requires the following properties in the configuration file:

 * DEV[0-9]*
   * NAME : string (e.g.  "white Light Source SX")
   * CONNECTION : chat connection string (e.g. "!tcp://nport-luci3:4001")
NAME
the name of the white light source device.
CONNECTION
the location of the device given as a chat location. If there is a direct serial line connection, the location is of the format "tty:/<device path>:<baud rate>:<number of bits>:<parity used> (e.g. "tty:/dev/ttyS0:9600:8:no"). If the device is accessible via a serial device server the location has the format "tcp://<hostname or IP address>:<TCP port number>" (e.g "tcp://192.168.0.1:4001").

Automatically Generated Properties

Basda Device

Every white light source basda device created the following properties during construction:

 * DEV[0-9]*
   * ABSOLUTE_MOTION.POSITION_IN_STEPS : int
   * ABSOLUTE_MOTION.COMMAND : Completion
   * CLOSE_SHUTTER_FULLY : Completion
   * ERROR_MESSAGE : string ("no errors" if the hardware has no problems)
   * IS_HARDWARE_REACHABLE : boolean
   * LAMP_STATUS : string ("ON", "OFF", "probably ON", "probably OFF", or "UNKNOWN")
   * OPEN_SHUTTER_FULLY : Completion
   * PRESENT_POSITION_IN_STEPS : int
   * RELATIVE_MOTION.POSITION_IN_STEPS : int
   * RELATIVE_MOTION.COMMAND : Completion
   * RESET : Completion
   * SHUTTER_MOTOR_START_POSITION_IN_STEPS: int 
   * SHUTTER_MOTOR_END_POSITION_IN_STEPS: int
   * SHUTTER_STATE : string ("closed", "fully opened", "partially opened" or "unknown")
   * TURN_LAMP_ON : Completion
   * TURN_LAMP_OFF : Completion
ABSOLUTE_MOTION.POSITION_IN_STEPS
the argument for the absolute motion command in unit step.
ABSOLUTE_MOTION.COMMAND
the Completion node for triggering one absolute motion.
CLOSE_SHUTTER_FULLY
the Completion node for closing the shutter fully.
OPEN_SHUTTER_FULLY
the Completion node for opening the shutter fully.
ERROR_MESSAGE
the fault status in a human-readable format.
IS_HARDWARE_REACHABLE
the status property for hardware reachability.
LAMP_STATUS
the status property for the lamp status.
PRESENT_POSITION_IN_STEPS
the status property for the current position in unit step.
RELATIVE_MOTION.POSITION_IN_STEPS
the argument for the relative motion command in unit step.
RELATIVE_MOTION.COMMAND
the Completion node for executing one relative motion.
RESET
the completion node to reset the hardware driver.
SHUTTER_STATE
the status property for the shutter.
SHUTTER_MOTOR_START_POSITION_IN_STEPS
the absolute motor position where the shutter is fully closed.
SHUTTER_MOTOR_END_POSITION_IN_STEPS
the absolute motor position where the shutter is fully open.
TURN_LAMP_ON
the command property for turning the lamp on.
TURN_LAMP_OFF
the command property for turning the lamp off.

Basda Service

  SVC.WORK_INTERVAL: Time
SVC.WORK_INTERVAL
The sleep duration before updating the property values by reading out the hardware.

Topic revision: r5 - 08 Aug 2018, AndrewColson
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