Tech Tip: OPT2041 Fiber Optic Sensor Quick Start

This sensor works with both Plastic and Glass fibers. Keep in mind that the color and reflectivity of the object determines the detection range capability of the sensor when used in reflex mode. The brighter the object reflecting the light, the easier it will be to detect. For example this white object is easily detected, but this darker object at the same distance isn’t detected because it doesn’t reflect as much light. There are 4 connections via this M8 connector – Supply, signal-out and contamination out. AutomationDirect does have cables that work with this M8 connector. You can mount it via 35mm DIN rail or Side mount via these screw holes. Beware that there is a max ambient light spec. Bright sunlight can be greater than the 10,000 Lumen max. spec. you will want to avoid using these in direct sunlight. And my favorite, this sensor has a high contrast Organic LED display that eliminates all the button press guess work of other sensors with easy to understand menus. And This bar graph of the signal strength is awesome when trying to setup the sensor or debug why it isn’t working because you can see at a glance how much light the object is returning to the sensor. This line on the bar graph is the detection threshold – objects reflecting more light than will be detected. And the width of that line is the width of the hysteresis. You can also see a numeric version of the signal strength and an output status. If this output status is blinking, that’s an indication that the signal is weak and the sensor optics might be dirty or fouled and need to be cleaned. And the best part of all of this is is you can customize the display to show only the items you want to see. We’ll see how to do that in a couple minutes. So … Let’s take a quick walk through this sensor’s menu structure, do some quick examples of most of these features and point out things you need to know along with some other helpful hints. Here we go … This sensor has 6 teach modes to automatically set the correct sensing distance and a manual way to set the detection distance. There’s a real good explanation of what all the teach modes are in the Family Overview video so we won’t go into that here, we’ll just walk through how to set each one up on this sensor. For Normal Teach, press the Enter button and down arrow to bring up the Teach menu and press ENTER to drop down into the Teach sub menu. Normal Teach is the first one so hit ENTER. Place the object in front of the sensor – notice that we are at a signal strength around 600 - and hit the T button. The display tells you the teach was successful. This vertical line here on the signal strength bar graph tells you where the cutoff is – that is we taught here at around 600, but any object that crosses in front of the sensor as low as around 300 will be detected. That’s important to understand – Teach automatically adds in a buffer so you don’t need to worry about that. Hit the Enter button to exit. Arrow up and hit ENTER to go back to RUN and sure enough the sensor detects object down to about the mid-300s. Notice that the vertical bar has some width to it – that indicates the hysteresis region. The signal has to fall below that region before the sensor status will indicate loss of detection. Minimal Teach is the exact same thing, but let’s do it anyway so we can if we get a different result. Enter into menu, down to teach, enter into teach sub menu. Down arrow to minimal and hit enter. Let’s do the exact same thing – set the object near 600 and hit T for teach – and it was successful. You can already see the buffer is a lot smaller with minimal teach –isn’t it. Looks like it is around the mid to upper 400s. Remember – Minimal Teach has a minimal buffer. Hit the Enter button to exit. Arrow up and hit ENTER to go back to RUN and sure enough the sensor detects object down to the upper 400’s. Exactly what we expect. To setup Dynamic Teach, we drop down into that mode but this time, don’t have any objects in front of the sensor. Here I have the sensor looking down on my pretend conveyor belt. We start Dynamic Teach by pressing T1 – it says its recording - then start the conveyor and have objects pass by. Press the T2 when done. The sensor automatically places the cutoff where it thinks the optimal place is between the two objects – looks like this one is at 540. So if we go back to RUN, sure enough we see that the large object IS detected, but the smaller one is not. Perfect. Two-point teach is the same as Dynamic except you manually choose the points. Put the first object under the sensor and press T1. Put the second object under the sensor and press T2. And since we used the same objects – guess what – we got the same answer. And sure enough in RUN mode, the sensor only detects the larger object. In Window Teach you put the object in front of the sensor and hit T1. And if I move the object out of the way, you see two lines – any object that passes between those two levels – or within that window of values - will be detected. Let’s go back to RUN and if an object is too far away it won’t be detected and if it is too close it won’t be detected. Only objects within the window will be detected. You can adjust the size of that window in the Window Size menu. The window width is currently set to these two values, just use the plus and minus keys to make it bigger or smaller. You can also move the center of the window – or ANY teach threshold with the Potentiometer menu. This number tells you where the current object is. This number is the threshold. Use the plus and minus keys to move that threshold around. The final teach mode is background. Just point the sensor at the background, and hit the T key. The sensor automatically sets the threshold just above the background There is also a hysteresis setting you can adjust just like all the others. The only catch is the amount of hysteresis you can use depends on the sensitivity you set for the sensor. This sensor is on High Sensitivity so I can only select a hysteresis of 45 to 200. On normal sensitivity you can change hysteresis from twenty to two hundred. External Teach does the same thing as what we just did, but instead of pressing buttons to select the thresholds, you apply 10 to 30 volts to pin 2. External Teach isn’t a menu item, when that voltage is applied the sensor, it will re-teach the detection threshold as if the sensor was in whatever mode you last taught. So you have to teach a mode via button presses first and then you can use external teach. Also, you can’t do Two-point teach via external teach and dynamic teach teaches as long as the voltage is applied. You can select the output type to be PNP or Push and Pull. The title of this sub menu is PNP NPN and there is a menu selection item for NPN, but you can’t actually select it on this sensor because the extra pin you would need to add an NPN output is used for the teach input. You can select Normally Open or normally closed. Some folks call that “Light-On” or “Dark-On.” For On-Delay you can change the value from zero to 10000 millisecond. And Off-Delay is the same. You can specify an impulse output instead of a discrete hi or low and specify the width of that impulse. Notice that every time a digit cycles it starts incrementing the next digit so getting to large numbers is pretty quick. Let’s set it to 1 second and exit back out to RUN mode. If we put an object in front of the sensor head, we see the output only lasts for 1 second – exactly what we expect. Operating mode is where we set the sensors sensitivity we mentioned earlier. The high sensitivity setting is for extending the detection range so we can detect objects that are a little farther away. You can filter the signal to reduce false alarms. There are eight filter settings but beware, each one reduces the switching frequency of the. The sensor’s switching frequency is how fast it can make a decision. You can rotate the display which is handy if you have the mount the sensor upside down. You can adjust the display brightness You can zoom the bar graph. You can even specify which display elements you want to see on the display. You can choose the language of the display And you can see the firmware version of the sensor. And finally you can do a factory rest and you can set a password which will prevent others from changing your settings. That ought to be enough to get you going. If you have any questions, please contact AutomationDirect’s free award winning tech support during regular business hours. They will be happy to help. And don’t forget the forums. There are lots of folks there that love to share their years of experience. Just don’t post any questions for AutomationDirect’s support team there – they don’t monitor the forums on a regular basis.