Laser LS8000-3 manual Dual Switch Configuration

LaserSpeed 8000-3 Instruction Handbook

Interfacing with the LS8000-3

When the product enters the measurement area and triggers the switch, the Material Present signal should activate. This causes the LS8000-3 to start counting length at 0. When the product leaves the measurement area and the Material Present signal deactivates, the LS8000-3 will calculate the final length and the measurement is complete. If in Final Length mode, the LS8000-3 will transmit the Final Length over the serial/Ethernet ports.

Dual Switch Configuration

Two optical switches can be connected in parallel in order to further increase the precision of part-length measurements. This configuration is typically used on discrete part measurements that are long and have a very tight length specification. The LS8000-3 repeatability specification is ±0.02% of the measured length.

Example:

A cut-to-length application has a product that varies from 14 ft. (4.27m) to 16 ft. (4.88m) in length, and has a tolerance of ±1/8 inch (±0.125in./±3.2 mm.) The LS8000-3 repeatability specification for a 16 ft. length is a little more than ±1/32 inch (±0.97mm.) While this is better than the length specification, the measurement variation is only about ¼ the length specification. Ideally, a measurement instrument's variation should be 10X smaller than the specification it is required to measure.

In order to improve repeatability, the LS8000-3's measured length can be reduced by using two optical switches to gate the LS8000-3's measurements. The LS8000-3 will only measure while the product blocks both optical switches. In this case, since the minimum part length is 14 ft (4.27m), the switches could be placed 13 ft (3.96m) apart. This will reduce the length that the LS8000-3 measures to between 1 and 3 feet. The repeatability will then be ±0.02% of 1-3ft instead of ±0.02% of 12-16ft. The new repeatability would then be ±0.0072 inch (0.18mm.) Because the distance between the two switches is fixed, this value can be added to each length measurement that the LS8000-3 produces using the Length Reset Value Setting ($R configuration setting.)

The optical switches should be arranged and wired as shown below:

Part No. 93463 / Drawing No. 0921-01561 Page 47 of 221 Revision A (Sep 2007)