A competitive analog LDT back to the PLC was used by an OEM to measure a windshield’s shape. A problem occurred with the PLC. The PLC’s scan time with an analog input was more than 40 ms, and the customer was unable to perform quality control with readings of more than 40 ms.
The 952QD BlueOX LDT with quadrature output was directly installed into the PLC High Speed Counter, which had the potential to generate an interrupt and hence could process the data much faster.
- Direct connectivity to the PLC High Speed Counter
- Sensor is absolute with the “Burst” Mode
- Increase in throughput
Customers could increase their throughput time by over 25% since the PLC was able to respond faster to the quadrature input than to the analog input.
The Gemco 953 VMax LDT also has the ability to provide continuous absolute position feedback in the harshest environments.
A car battery OEM was looking to achieve enhanced quality control in the manufacturing process. While going down the line, the battery is in two pieces and its top and bottom halves are melted and compressed together. In case they are not accurately sealed, there will be a leak in the battery acid and the battery will have to be scrapped.
The distance between the two halves was monitored by installing a 36" 953 VMax LDT. To monitor this dimension, the 953 VMax’s position was wired back to the PLC of the customer.
- Consistently maintains a repeatability of 0.001”
- Less scrap material
- Absolute feedback, no need to re-calibrate or re-home in the event of a power loss
- Maintenance not required
Highly accurate and repeatable feedback was provided by replacing limit switch sensors with a Gemco LDT.
Windshield Glass Kiln
An A-B PLC 5 with 1771 I/O rack was used by a manufacturer of glass products for automotive customers to regulate a complicated glass kiln process to bend the shape of the windshields. The kiln process was control-intensive and mandated a resolution greater than the 12 bit provided by the existing solution. Upon using the AMCI card, the outputs can be accessed only from the front of the card, which requires an A-B input card to observe the PLS output status in the I/O image table. Moreover, a number of PLS outputs are used in the kiln process to establish position-based windows in which process events had to take place. Usage of the AMCI card mandates the use of an extra A-B input card and also additional PLC logic to carry out these functions.
Apart from being fast, the 1771 Ultra High-Speed PLS is also smart. It provides 14-bit resolution, the Input Capture and Input Warning Map Register are in-built and directly fed to the I/O image table, and the 16 PLS outputs are directly sent to the I/O table, thereby eliminating the need for the A-B input card.
- Eliminates the need for the A-B input card
- Frees a slot in the rack
- Eliminates the cost of writing additional code
- Minimizes logic overhead in the system
The 14-bit accuracy of the 1771 enabled the customer to have a better control over the shape of the glass, leading to less scrap material.
This information has been sourced, reviewed and adapted from materials provided by Ametek STC.
For more information on this source, please visit Ametek STC.