Chapter 4 Software Communications - THORLABS ULN15TK User Manual

Ultra-Low-Noise Laser System
Chapter 4 Software Communications
Each device is equipped with an USB mini-B style connector for USB communication with a host device. The device
will enumerate as a Virtual COM port on the host device. For Windows PCs running Windows 10 or later, no special
driver is required. For Windows PCs prior to Windows 10, the driver included as part of the firmware update utility
is required.
All communication queries must be terminated by a single carriage return character (\r) or a combined carriage
return and newline (\r\n). Communications originating from the device will be terminated by one or more
combined carriage return, newline pairs (\r\n). A connected host should not attempt to send additional queries
until a response has been received from the device. Most queries will result in a response within 10ms. Queries
requesting the saving of configuration parameters will result in longer response times.
The commands sent from the USB interface enable the following functions:
•
Turning the laser on or off
•
Reading status of the laser, and values of the laser temperature set-points
•
Adjusting the temperature set-points for the chip and the FBG
•
Adjusting the drive current of the laser
•
Setting the external temperature modulation port function. The default for this port is to be disabled, but
it can be changed to adjust either the chip or the FBG temperature based on the analog voltage applied
to this port.
In addition to the USB port, a RS-485 port has also been included on the back panel of the system. This port, a 9-
pin D-Sub, can be used with the same command set outlined in this chapter through the RS-485 communication
protocol. Please refer to the last sub-section in this chapter to see the pin-out of the D-Sub connector.
Command/Response Structure
All commands are text based with the basic format as follows:
command [param1 [param2..[paramN]]]
Proper syntax will be specified for each command in the following subsections. Each command will be followed
by a corresponding response with the following format:
Response_code:Response_Text[command_response]
Note that all commands and parameters are lower-case letters.
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Chapter 4: Software Communications
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