Posts: 1
Joined: Thu Feb 01, 2018 12:09 pm

Job Posting - Rasberry Pi and PLC Integration for measurement of current, voltage and optical power

Thu Feb 01, 2018 12:24 pm

Hi Guys,

I'm not sure which board to include this request so I added it here. If there is another location to post this topic, please let me know.

Our company is looking to integrate raspberry pi 3(slave device) which will perform measurement of current, voltage and optical power. The raspberry pi will communicate with our Omron PLC via Omron communication protocol.


The Laser Tester Module (based on Raspberry Pi) will be used for testing lasers and the Laser Tester Module (Slave) will be connected to PLC (Master) which will have an online dashboard to provide test report data, testing automation sequence and alert notification during testing process. The PLC dashboard will allow local remote access to observe or conduct the testing process in real-time. See Below Block Diagram

The Laser Tester Module

The designed reliability tester will be used for Constant Current, Constant Power and LIV tests.

Project Description

The Laser Tester Module (Slave, Raspberry PI ) will perform measurement of current, voltage and optical power from a monitor diode of 64 laser diodes to Set and Maintain Constant Power Control of the device or Constant Current and send the information to PLC (Master) during the test. The test station will consist of:

1. PLC driver needs to be developed to communicate with the Laser Tester Module (Rosebery Pi) to control/select and measure the following:
• Bias Laser Current of 64 circuits (Sampling Resistors)
• Laser Optical Power of 64 Circuits (Sampling Restores)
• Laser Diode Forward Voltage of the 64 Circuit
• Automatic Constant Power Control – Close loop Required for dedicated Laser Driver IC to be used.
• 8 X 8 Channel Digital to Analog Outputs will be used to calibrate the laser driver output and adjust the optical power
• Automatic Constant Current Control -. Close loop Required for dedicated Laser Driver IC to be used.

2. An Interface board will be provided to execute address decoding of each selected part for testing and provides the necessary hardware for measurements for Laser Test Module

Functionality of the Hardware & Software

1. Output addresses based on 8 Banks X 8-part locations (2 x 3 Bit outputs)
• One 3-bit address for the bank location and the other 3-bit address for part location plus 1 Chip select
2. Measure the optical power, bias current, forward laser diode voltage of each part location under two modes: manual or automatic mode – 64 readings
• Manual mode will be selectable via user interface with a selection button.
• Automatic mode will be a default setting for the tester will commence its measurement of the default matrix (64) as soon as the Start button is pressed in 1 second step intervals (User selectable).
3. Th Laser Test module (Slave) will communicate with PLC (Master)via Ethernet
4. The measured values will be downloaded to Server/PC
• Bias Currents
• Forward Laser Diode Voltages
• Optical Power
• Case Temperatures
• Ambient Temperatures


• Number of components to be tested 64
• Diode Temperature Range 20 to 150°C
• Control Loop ACP (Automatic constant power), ACC (constant current - Dedicated IC
• Laser Current Range 0 to 1000 mA @ 0.1% reading error
• Photodetector Current – 80 μA-1000 μA
• Voltage 0- 5 VDC 0.1% reading error
• Photodiode Measurement – Via sampling resistor
• Software - YES
• Drive Type – Individual (64 individual channels)
• Stability +/- 1 mA (1000 hr FS)
• Temperature Stability ±0.2°C
• Dimensions 800 x 800 x 800 mm
• Power Requirements 115/230 VAC; 50/60 Hz; Single Phase; 3A

Please message me or email me if you are interested in this project: pherniak @ (i put a space inbetween the @ symbol)



Posts: 8
Joined: Tue Jan 02, 2018 11:32 am

Re: Job Posting - Rasberry Pi and PLC Integration for measurement of current, voltage and optical power

Fri Feb 02, 2018 7:10 am

Hi Patrick,
Sent you an email.
Hoping for prompt response.

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