When several systems (i.e. ArcWorlds) are installed in the same area there is a possibility for the light curtains to interfere or cross-talk with each other. An problem scenario could occur if the ArcWorlds are installed in a row, as a production environment and layout could do for maximization of space. In this case the emitters from non-matching may be seen by cells further down the line.
In the example that follows it would be possible for the emitter at Cell A to send signals to the receiver at Cell B and Cell B as they are installed collinearly (in a row). Cell B's emitter may also be detected by Cell C's receiver.
A solution to this problem is to change the scan codes on the cells. When these systems are built at the Ohio facility the scan codes on the light curtains will be set to 00 for all light curtains. A solution to this interference would be to set the following:
- Cell A -- scan code 00
- Cell B -- scan code 01
- Cell C -- scan code 10
This should resolve the cross talk. Whenever changing the scan codes, it should be changed on all items in the cascade (both the horizontal and vertical light curtain elements if both exist).
An additional approach would be to alternate the sender and receiver location on alternating cells. This staggers the distance between the pairs in the next cell. Applying this technique in addition to the scan code can result in robust cross talk avoidance planning. This requires planning in advance or knowing the layout of the factory.
Another solution would be to install a physical barrier between the cells. For example a large piece of cardboard can be placed between cells to test if interference is occurring. If the light curtains behave better with the blocking cardboard present, we learn that a more permanent solution is necessary. A fixed solution could be implemented with sheet metal panels behind the emitters at Cell B and Cell C. This is left to the customer or an application by application basis.
Comments
0 comments
Please sign in to leave a comment.