Captain's Log: Monitoring machine run times with data-logging solution
A manufacturer of screw machine products wanted to track the operating time of the different machines in his shop to see if there were particular machines and operators that were more productive than others.
For this project, the company wanted to accumulate both the run times and down times over a standard eight-hour work day. However, it was typical for these machines to be down several times during the day for normal operations such as while loading in additional raw material or changing tooling. To accommodate this, the manufacturer required monitoring equipment capable of determining not only how each machine was running, but also how long it was stopped, and not begin accumulating downtime until the machine had been stopped for more than 10 minutes.
The customer chose the CAS DataLoggers dataTaker DT80 data logger for this project because of its flexible programmability; it could be set-up to track both the runtime and all stoppages lasting longer than 10 minutes. With multiple monitoring schedules and up to 15 analog inputs, the dataTaker could also monitor several machines simultaneously. To simplify installation, the customer decided to use simple split-core current sensors on the power lines for the main drive motors. The datalogger could be configured to read the current and trigger when the current was above a threshold value indicating that the machine was active. The dataTaker could store as many as 10 million data points in its user-defined memory, enabling independent control of schedule size and mode so that it could be setup to log only as long as needed. The stand-alone logger also featured a built-in display and provided reliable low-power operation.
Users created a program for the data logger to sample each of the inputs corresponding to the current sensors for the different machines once every 30 seconds. The current from the motor was compared to the threshold value, and if it was greater, a running flag was set indicating that the machine was active. However, if it was less than the threshold, an internal idle counter was incremented, indicating that the machine was idle. This idle counter was then compared with the limit value of 10 minutes, and if the count exceeded this value, the run flag was cleared to indicate that the machine was down. Once the machine restarted, the run flag was set again and the idle counter reset to 0 to prepare for the next event. Finally, another schedule was programmed to look at the run flag every 30 seconds and to increment either the running or the down time totals for the day. At midnight, the total were saved and then reset to prepare for the next day’s operation.
The dataTaker’s included dEX software simplified configuration and was user-friendly for novices. Operators could create mimics to view real-time data, create trend charts and tables, and retrieve historical data for analysis. This built-in software ran directly from a web browser and could be accessed locally or remotely anywhere that a TCP/IP connection was available including globally over the Internet. Operators could use any of the logger’s built-in communications ports to view dEX including Ethernet, USB and RS-232.
Additionally, the shop’s floor supervisor prepared a summary page that allowed him to view the accumulated data at any point during the day to immediately spot any potential issues. Then the daily totals were downloaded to an Excel spreadsheet to allow trending of performance over weeks or months to help identify more systematic problems that could be related to a particular machine.
The manufacturer’s shop productivity increased as a result of installing the dataTaker DT80 intelligent datalogger due to its ability to identify the highest and lowest producing machines and operators. The dataTaker’s versatile programming capabilities, large memory, and user-friendly software enabled the customer to track all his machines’ run and stop times and also view and organize the data in convenient spreadsheet format.