Prior to implementing this solution, the client had the hardware in place for six individual thermal and power measurement testing stations, but did not have an efficient means of control and data collection. The data from each of the test station components had to be logged separately, often by hand (DAQ unit for thermal measurements, Power Monitor for AC tests, and DC Power Supply for DC tests). For tests that could last an entire day, this was recognized as being inefficient and the client decided to automate the testing procedure.
DMC was tasked with creating an automated, multi-station testing system using the client’s existing testing hardware. LabVIEW was used as a platform for the testing system. Because there were to be six test stations, each with identical capabilities, it was decided to implement the system by creating a single testing system state machine and then dynamically launch clones of this machine (one for each of the six testing stations) from a master user interface. There were several advantages to this design, most notably that it would not only reduce our development time (and our client’s cost), but would also allow for maximum flexibility and future expansion.
The client designed and tested both AC and DC lighting fixtures and had to be able to test both. For the AC tests, a Yokogawa PR300 Power and Energy Monitor was used to monitor voltage, current, and power for the duration of the test. For DC testing, a Kepco KLP DC Power Supply was used to both provide a voltage/current source, but also to monitor voltage, current, and power.
A Yokogawa MW100 Data Acquisition Unit was used to acquire analog data from up to 60 thermocouples. Additionally, the Yokogawa MW100 could be configured to operate using several other I/O modules, including analog and digital output modules. While the Kepco DC unit was capable of turning the power on/off, the PR300 Energy Monitor was not. So a digital output module on the MW100 was configured to turn AC power on/off through a relay.
Ultimately, the client received a system capable of operating six independently configurable thermal and power measurement testing stations. Each station can be configured to run AC or DC tests - for DC tests, either constant voltage or constant current modes could be used. A system configuration file is used for each system to select test hardware, I/O installed, thermocouples to be monitored, the sampling rate, the test duration, emergency stop temperature, voltage, current, and power limits. Testing on any station could be independently started, stopped, and configured. With the flexibility of the system, the automation of the data acquisition, and the ability to independently control and monitor each station from computer, the client is able to be much more efficient and productive in their testing process.