Software for the LDC1300B Controller
Standard software application packages, drivers, and programming guide.
PC Software Interface
Below is a full screen shot of the layout of the main Laser Diode Controller (LDC) window. The screen is divided into six main panels: Main Chart Display (upper left), Instantaneous Measurement (upper right), Current Source (lower left), TEC Drive, Communications, and Connection Status (bottom right). To establish communication between the PC and the Laser Diode Controller, choosing the correct COM port in the Connections window and pressing the "CONNECT" button. Once connected, the main LDC screen will update the device parameters continuously. Instantaneous measurements are displayed in the Measurement portion of the main screen, while a rolling chart of the active measurements is displayed in the main area. The user can select which measurements to display via toggle switches in the Measurements section. The graphs can also be easily re-scaled. To end the session, simply click on the "QUIT" button in the lower right-hand corner of the screen.
Figure 1. Full Screen Shot of the main Laser Diode Controller window
Once a device is installed, the LDC main panel will immediately show the device temperature being monitored. The device set point can be changed either by typing the desired value directly into the "Set Temperature" box on the TEC Controller portion of the main screen or by using the up/down arrows to change the temperature in 0.1oC steps. The TEC tuner window is selected from the Functions menu as shown in Figure 2 to the right.
If the TEC's temperature is stable, temperature traces will settle to a steady value after a short period of time. If the temperature of the TEC is unstable , oscillations of increasing magnitude will be evident in the temperature trace.
The LDR features a safety lockout mechanism to reduce the risk of damage to the device as a result of improper TEC controller settings, incorrect TEC wiring, or inadequate heat sinking. If the temperature deviation is ever larger than 0.5 oC for a period of time exceeding the set "Lockout Time," then the TEC and current source are both locked out. The lockout time, which has a default setting of 30 units (about 10 s), can be adjusted by the user.
The current source (refer to Fig. 1) is turned on/off by clicking the "ON" button. Upon activation, the set current is applied to the device, and the LED indicator light is illuminated.
Prior to activating the current source, set the current limit for the device. To change the set current, either directly type it into the box or use the slider button. As the current is changed, all monitored parameters will be displayed and automatically updated in the measurement panel and graphically in the main window.
If preferred, the current source can also be used in constant power mode. In this case, set the desired power in dBm (or mW). The driver will then try to maintain the set value using feedback from the photodiode.
Standalone Driver Configuration
The board can be used as a standalone driver. Under the Functions Menu, you can select "Save Settings" to save the state of the board to non-volatile memory. The driver will then boot up in this state every time power is applied.
The software included with these controllers is capable of producing L-V-I [Optical Power (Light)-Voltage-Current] plots that can be viewed on the screen or exported in .csv (comma separated value) format for use with other programs such as Microsoft Excel.