av8or1

Hi- How are you? I am looking for a little guidance regarding the selection of a micro controller for a home project. I did a search on this forum but didn't come up with what I was looking for, so I thought I would post my question here. Hope it is ok. My usage of the controller won't involve the governing of anything vital or anything that could harm someone (like a saw, etc.), just lights mostly and possibly one small fan. With that in mind I had tenatively selected the AB Micrologix 1000. However I cannot decide on which model to get. I'm looking at the 1761-L32AWA or 1761-L32BWB ... the inputs will consist of sensors (proximity sensors, photo-reflective sensors) and the outputs will provide the control signals (switching) of lights. I'm guessing that the BWB is the way to go in this case, but I am a complete newbie with this stuff. I am a pure software guy, so learning the ladder logix stuff was relatively easy, but getting that to work with the real-world stuff isn't something that I deal with at all really. So any input would be greatly appreciated. Thank you, Jerry

All- Ok the weather cleared up today, so I made the final progress video demonstrating the "finished" product. I placed finished in quotes only because there are still a couple of cleanup type items that I need to do, but they are quite minor and don't involve any modification to any part of the system. (example = returning my tools to the outbuilding, etc.). Let me know what you think. Thanks again for all of the help! Jerry

QUICK UPDATE: All- Well as of tonight I can report that I have completed the project! Wooooo-hooooooo! I have the traffic light mounted to the garage wall, the stray-reverse warning buzzer mounted and wired into the jbox, the cooling fans set in place/working, the wiring cleaned up and the regression testing finished. All is well! A few things that somehow seem noteworthy (though perhaps obvious): 1) Weather will play a factor WRT the successful operation of this system. The green light, stray-left and stray-right sensors are all mounted at the very mouth (entrance) of the garage and as such are more susceptible to weather phenomena than the other sensors. And really, it's not the sensors themselves so much as it is the reflectors. It has been raining quite a bit in Austin the past few days and I have learned just how that particular form of precipitation can cause havoc with the system. In the end I think that I will need to tell mom that if it is raining when she comes to visit, that she should ignore the stray-left and stray-right sensors. Green light won't be a problem because the water will cause the reflected light to fragment, so the sensor won't perceive any returned light, so being a dark operate sensor it will send 24VDC to the PLC, which will cause the green light to illuminate. So basically you'd see an open garage door with a green light already illuminated. Not a huge issue. 2) I learned the hard way that laying down long strips of reflective tape to match the length of the track lighting wasn't the best approach, at least not WRT the stray-left and stray-right sensors. That is because the garage floor is rather uneven (not noticeably to humans, but to a laser it is) laterally, so it was better to cut small strips of reflective tape, determine which position would cause the reflected light to be picked up by the sensor, and glue that strip down in that position. Then move on down the line, repeating that process. 3) When doing a project like this where your PLC is not located in an easily accessible area, you really need a good answer for the issue of implementing program updates/corrections, or tweaks as Bob referred to them. I don't like laptops and so I had to haul my desktop, monitor, keyboard, mouse, power cords and PLC interface cord up into the attic each time I wanted to make a program modification. By the completion of the project, the count stood at 5 so I would recommend devising a better plan than that. I didn't do so good there, but again, I just don't like laptops. Even so, I almost broke down and used one in this instance. I realize that this is a big "DUH!" but wanted to mention it anyway. Chuckle away Bob! Seems like there is more to discuss, but it's getting late and so it escapes me at the moment. As previously mentioned, I am VERY curious to see how this system will perform over the long run, after being exposed to the real world elements of a garage. It seems like it would be interesting to provide an update post regarding that subject perhaps in a year from now. But I digress. I plan to make a demo video tomorrow and post it. When I do I will provide a link for those who are curious. Once again, I would like to extend a big THANK YOU to all who contributed your wealth of knowledge to my project. I appreciate it! Jerry

Y'all- Made quick progress video tonight, mostly to take a break from the hassle of fiddling with the sensors and to have a little fun with it. Thought I'd post. Thanks, Jerry

QUICK UPDATE: Hope it's ok to continue with this project report... Well after a bunch of fiddling and fabbing about, I can state that I have achieved victory over the green light sensor!!! Woooo-hoooooo! The reflector is gorilla-glued to the garage floor and the sensor works repeatably. Of course, I realize that my victory may be short lived because I haven't seen yet exactly what will happen once the glue fully dries. And it began to rain tonight, so the reflector got a bit wet (we're only talking droplets here) and there was plenty of moisture in the air. Therefore I am interested to see if there are any resulting adverse affects. I'd think not, but that's still TBD. And while I am on the subject, this is actually the "last frontier" of the engineering-related questions I had at the outset of this project: how will this somewhat-sophisticated and arguably expensive equipment measure up over time and exposure to the real-world elements of temperature variance, weather phenomenon and human-generated "hazards" associated with the typical American garage? I thought about this for several nights prior to even considering launching myself into the fray. And I must confess that I had my doubts about the long(er)-term viability of such an implementation. Maintenance issues were an additional concern. That said, the decision to press ahead came with an interest to learn more about PLCs and PLC programming coupled with the rather simplistic notion of "you don't know until you put it to the test". So now will come that test. I am quite curious to see how the system will perform over time... But I digress. A quick little note that once said or read will seem quite obvious and even borderline "duh" territory, but the procedure that I found the most effective to establish a "proper alignment" between the sensor and the reflector such that you would enable the sensor's receiver to pick up the reflected laser beam was to switch off all of the lights in the garage, go completely "dark" and note where the beam hit the ceiling (or in this case it was occasionally hitting the garage door) in relation to the sensor. Sometimes it would be difficult to see where the reflected beam terminated, so I found that temporarily blocking the beam with your hand, then removing your hand and continuing that alternating pattern briefly would cause enough of a light differential that the human eye could distinguish the reflected beam's end point without too much difficulty. Also of note is that even the slightest perceptable movement of sensor or reflector to the human touch makes a significant difference to the sensor. So I ended up using the handle-end of a screw driver to ever-so-lightly tap the sensor around its mounting axis and ever-so-small shims for the reflective tape (prior to the sticky-back covering material removal of course). Also, I have mounted the garage door sensor with a custom L-bracket attached to the top inner rib of the top garage door panel. As anticipated that went smoothly and quickly. I then drug everything up into the attic (again) and reprogrammed the controller to reverse the logic of the garage door sensor. Now code/logic works correctly. The ironic thing is that the red light sensor will occasionally discontinue proper operation, due to a small shift in how the traveller (or come-along piece) rests in the track lighting case. So that will require more fiddling on my part and I am a bit concerned about it because I plan to use the same approach with the stray-left and stray-right sensors, which are next on the project's agenda. Oh well, I suppose it's just more fiddling at this point, much like the green light sensor was. Keep you updated, thanks! Jerry

Bob- Thank you for the tip! I hadn't heard of panduit before now. Learn something new everyday! Well I thought that things were kinda downhill now that the sensors were working reliably. Eh, not so fast. I have successfully mounted the yellow light and red light sensors and they work without much hassle. I plan on installing the garage door sensor tomorrow night and expect it to go even smoother. However the green light sensor has been another story. I just cannot get the proverbial moons to align (literally) so that the sensor's receiver picks up the emitted laser beam off of the reflector. The problem appeared to be with the mounting of the sensors to the ceiling. So I called the local distributor and bought some 18mm sensor-specific mounting brackets. The first set were adjustable but not right for this application (no way to lock them down into position). So I returned them and bought a set of more "rigid" brackets. Those definitely improve the situation, but the green light sensor is still giving me fits. It has to do with the mounting of the tape on the floor and possible interference from the bottom of the garage door and/or the garage door spring boom. I did get it to work reliably once or twice, but the tape wasn't glued down and it was quite difficult to repeat. So I suspect that more "fiddling" is in order. And this one is for you Bob: I realized that with these new sensors being dark operate I'll need to reverse the logic of the garage door sensor's PLC program contact. So that means dragging the stuff up into the attic again. hahahaha! I'm attaching a picture of the red light sensor mounting and the green light sensor mounting. The red light sensor is kinda cool in that I ended up needing to custom-fab a slide-along piece that could fit into the track lighting casing and also receive the sensor mount. That worked out and so now I have a little over two feet of travel to manually adjust the red light sensor position. The green light sensor picture simply illustrates the problem for you, it was taken from directly below the sensor with the garage door open. Still working..... Jerry

Hi y'all- A quick question if I may. Last night I was installing the fans in the jbox and doing a little experimenting. Not with the wiring or anything, that was straightforward. I ended up returning the controller and power supply and just wiring these two +12VDC fans in series, powered by one of the +24VDC terminal blocks. And so the fans are in and are running just fine. Anyway. In playing around with them, they seem to spin rather slowly and don't seem to put out a lot of CFMs. But that could just be my perception. They are quiet, that's for certain. So what's the issue then? Well I was experimenting with a rather simple concept really, but one that made me think a little bit. So I decided to pose it to the forum. The issue is the arrangement of these fans. I have two fan holes that came with the jbox and these holes already have fan guards on them. One is on the bottom of the jbox, the other on the top. Initially I thought I would mount the lower fan such that it draws air into the jbox from below and then mount the top fan such that it pulls air out of the box. Kind of a colder to hotter thing (hot air rises). However after the aforementioned experimentation yesterday, there didn't seem to be much air being drawn away from the microcontroller by the top fan. Therefore it almost seemed like a better idea to point both fans inward and then let the air escape naturally through holes that are in the sides (both) of the jbox. But it didn't make much sense theoretically ... the first option would seem to lend itself to be the better choice. I realize that it's a trivial concept, but given the temps that the controller is likely to experience in the TEXAS summer I'd like to implement the smartest choice. Thoughts? Thanks!

All- Well the sensors did indeed arrive on Friday. However the weekend has been packed full of stuff to do, so I only got around to working on the project last night. Not sure I can finish today, but will try. In the meantime I put together a quick video regarding the sensors, mostly for the fun of it, but I hope that it might help someone in the future. For the folk here who do PLCs and such everyday, the video is likely a bit pedestrian and perhaps a bit of a yawnfest, but hey. Again, the goal was to pass on a bit of what I have learned, just as those on this forum have done for me. The discussion is not fully comprehensive, but has a fair amount of detail to it. Have a look, I mention the forum in the beginning. Feedback welcomed. Jerry

ANOTHER QUICK UPDATE: I spoke with the local distributor this morning who inquired with AB regarding the sensor manufacturing process. He was told that these sensors are indeed made in Champaign, IL and not abroad. Apparently they were simply out of them and needed to manufacture a "new batch". So my sensors should be quite new. And according to the tracking number, they should arrive tonight. Therefore hopefully I can close out the project over the weekend. I haven't hung the light on the wall yet; I'd prefer to ensure that the sensors will work satisfactorily first. Anyway. Will post again when completed, hopefully this weekend. Thanks, Jerry

QUICK UPDATE: The fan setup I had just wasn't going to work. So I returned the fan controller and the power supply/adapter. I'll keep the fans and just direct-wire them into the system. They're 12V fans, so I can just put them in series and connect them to one of the +24V terminal blocks. Perhaps not the most ideal solution, but it will work. Still awaiting news on the sensors. Thanks, Jerry

Hi Bob, Well I was kinda concerned about it really, if to be open. Therefore I decided to investigate further and since I didn't know exactly how PC fans operated, the decision to implement something was a given. The specifications for the Micrologix 1000 are: Operating Temperature ... Horizontal mounting 0…55 °C (32…131 °F) Operating Temperature ... Vertical mounting 0…40 °C (32…104 °F) Nonoperating Temperature ... -40…85 °C (-40…185 °F) My mounting is horizontal on a DIN rail, which would seem to provide the best heat dissipation/cooling of any of the mounting options that I looked into, so I went with that. My attic has a radiant heat barrier on the inner side of the decking, which supposedly reduces temperatures appreciably. Eh. Even so, it seemed possible to me that the temps could push the 131 °F limit. Somehow though it still seemed like overkill. Overkill works for me though, so I went ahead with it. I have a +12VDC power supply/transformer, a fan controller and two fans. Unfortunately they aren't playing nicey-nice together, so I am still working on the configuration. The setup will be external to the PLC, though clearly, I will install it within the enclosure. Anyway. Thank you for the feedback from an expert. Good to know that I was on the right track. -J

Alright this is a little disappointing. The local distributor tells me that the AB folk in IL didn't have my sensors in stock, even though his computer screen said that they did. Apparently they are being shipped from overseas (?!?!) and won't arrive at the factory until Friday. So they may not ship until the following Monday (one week from today). That would mean that I wouldn't get them until next Friday most likely. Ehgad! I inquired with the distributor as to why this was the case. Was the sensor not actually built at the factory in IL? Is it an odd part that practically no one purchases and so it had to be special-ordered? His answers were basically 'yes' and 'no' but couldn't offer anything further really since he doesn't work for AB. So does anyone know how AB goes about manufacturing their products? Are some built in IL and others elsewhere? What gives? I am curious more than anything... Thanks, Jerry

bob -> Great video rig! I'll have to look into that in a few weeks when I go to find a replacement. gbradley -> Thanks! Glad it is received rather favorably here. I was a bit concerned at first regarding posting about the project at all, thinking that the experts here wouldn't be interested in a home project like this. But I am glad that I did. The advice received in this forum has been tremendous. UPDATE: Well the hopes of completing the project this weekend fell by the wayside on Friday. I returned home from work and became excited because I noticed a brown box outside my front door. Went to pick it up, all prepared to test and implement the sensor "front end" only to find that the box contained the reflective tape (AB 92-104) but no sensors. Wha-? The local distributor is quite good at getting you next day delivery when you purchase from them, but for whatever reason neither the tape nor the sensors (AB 42EF-P8KBC-F4) were available in the Austin, Dallas or Houston offices (Reynolds Company). So they had to be shipped directly from the AB factory in IL. Not sure at this point if it was an oversight or if the two component types are being shipped separately. I'll call the local distributor tomorrow and see if they can track it down for me. Anyway, maybe by early this week I can finish up. FYI. And one sidebar question if I may. In the heat of the typical TEXAS summer it gets rather warm in my attic. I mean really warm. So I came up with the idea of installing some PC fans in the enclosure to help keep the components cool. However in reviewing the literature it almost seems like it would be unnecessary, as the maximum temps for the controller and the power supply exceed the max temp that I would suspect can be reached in the attic. Still, I decided to go ahead and implement something since I - admittedly and embarassingly - didn't exactly know how PC fans worked. So I researched it, learned a fair amount and developed a design that would work somewhat well. Not ideal, but ok. So the question for you PLC experts is simply this: in your estimation would supplemental cooling like this be necessary in this design (enclosure in an attic)? Have any of your designs included some form of a cooling system? Thanks again, Jerry

That does sound like a nice setup. What is the storage media used? (mine is 8mm tape - if you can believe that! Early 90's vintage stuff) Here is a condensed version of the progress report, not sure it's worth posting here, but I thought y'all might be interested to see that I am at least making progress.

Thanks Joe! The traffic light passed regression testing last night, so all I need now are the sensors. Hopefully by Thursday or Friday. 'Would like to be finished by the weekend. We'll see. I made a progress video too, but had a mysterious difficulty in uploading it today. Have to go back and look at that again. My camera is getting quite old now, so it's just as well. I might need to re-shoot after getting something new. Will post when I have something viewable. Anyway.

Hi Joe, Well there are several possible solutions to the problem really. In my design, I am using an actual traffic light that was once in service somewhere in the USA. It's the old-school type that illuminates with simple 60W light bulbs running on 120VAC (as opposed to LEDs). Specifically, my system will involve 6 sensors in total, as it will provide both longitudinal and lateral guidance. I will have 5 lights to provide such guidance, and 5 of the 6 sensors will match 1-to-1 with those lights. The standard red, yellow and green will handle the longitudinal axis. Two additional lights in the form of red arrows will do the lateral stuff. The sixth sensor exists solely to monitor the state of the garage door (open/not-open). To address your question of vehicle length, my system keys on the red light sensor (or in your words the sensor at the "inner end"). That is, the system can manually compensate for varying vehicle lengths via the red light sensor's mount (adjustable). In this way, you can move the sensor closer towards the inner wall for a longer vehicle or towards the garage door for a shorter vehicle. Make no mistake about that however, I am not attempting any form of automated length adjustment. Rather, I am mounting the sensors via standard-issue track lighting such that all one would need to do is to pull the vehicle in question into the garage, make note of the ideal parking location, then simply get a ladder and manually move the red light sensor by hand such that the laser beam is broken right as the vehicle encounters the desired stopping location. Or slightly before that actually, factoring in a driver reaction time of some sort. Finally, this same means of adjustment will be applied to the stray-left and stray-right sensors, while the green light, yellow light and garage door sensors will remain in a fixed position. A couple of pictures of the assembled traffic light are attached for reference. I completed the final wiring of the light last night. Will do a rudamentary test tonight and maybe post a video of that test. Just waiting on the sensors now really. Hope to get them by week's end and finish this thing off by the weekend. Thanks, Jerry

UPDATE: Ok after a good long discussion with a couple of AB reps regarding sensors (prox/laser/ultrasonic/etc) I have decided to go with the LaserSight RightSight sensors and use the 92-104 reflective tape. None of the local AB distributors (Dallas, Houston, Austin) have either in stock, so they'll have to come direct from the factory. This means it will require 3 or 4 days to arrive. Feedback appreciated. Thanks! Jerry

Bob, Thought about you last night when I drug my PC, monitor, keyboard, mouse and power cord up into the attic so that I could add the buzzer logic and change one of the outputs to a different channel. Because of cord lengths I had to do some interesting contortionism with both me and the components in order to make the modifications too. It was one big mess of stuff running this way and that. Interesting. And then take everything back down again, of course. Having something as you describe above sure would have been nice. And FYI ... still debating/researching the sensor thing. Thanks, Jerry

All- Wow, thank you for the feedback, I appreciate all of your ideas. They are all quite sharp in their approach! With specific regard to the notion of employing ultrasonic sensors, I investigated that option during the project's early days but didn't feel comfortable with some of the literature I read regarding the "beam width" associated with that type of sensor. There were claims of it being narrow throughout its range, but I couldn't see how it couldn't be interfered with. And so I was concerned about getting false positives, though I could have been off-base with such thinking. I read some more tonight about it and pretty much arrived at the same conclusion, though I learned more than the first time out. Also, the only ultrasonic sensor that had the range and narrow beam width was 48VDC, which would mean some re-tooling of the current system to make that work. Naturally, I could have missed others that are 24VDC and there were AC options but that too would require re-tooling of the already-existing configuration. I'm not opposed to that, but if I could use what I've already risked life and limb to run in the never-reaches of my attic space, I'd prefer to go that route if possible. So I called AB again today to get more information regarding the RightSight LaserSight sensors. My key question involved the reflector: what type of reflector would I need in this application (3 - 10 ft) to make that sensor work? The basic answer was that if I didn't go with the recommended reflector (AB #92-118) then using the 8.5" x 11" reflective tape (AB #92-104) would work with a laser sensor and would likely yield acceptable margin in that range rather easily. That said, the reflective tape that I currently have (AB #92-99) will not work with a laser sensor at all, so it would be a throw away. At only ~$9, no big deal, but what I didn't and don't want to get into is to have these little reflectors that are like miniature hockey pucks that are raised off of the garage floor. I could just see them getting crushed by the vehicle at some point, then I'd need to clean up the mess and buy a new reflector. And depending on how often that phenomenon occurred, that could get pricey. Reflective tape on the other hand will ahere to the floor with almost no raised section, so if it is run-over, no problem, just clean it off if you need to and keep going. The AB engineer also confirmed the answer to my question I had when considering #92-104: "Could I cut this sheet-of-paper sized reflective tape into smaller pieces?" It seemed like an obvious 'yes', but the issue that often rears its ugly head to bite you during implementation and testing involves the one question that you didn't ask, so I decided to ask anyway. That said, I plan to give it another day or two of research before making a decision. If I had to decide right now, I'd go with the AB option. So we'll see. Again, thanks so much for the input! Jerry

Hi John, Well I appreciate the feedback from an IA professional. There's been a considerable amount of valuable guidance on this forum, so thanks to you and all who have contributed, I appreciate it! I will look into that telco prox. The laser sensors that I am considering are a bit cheaper at ~$90 each and I already have the cabling in-place, but if I end up needing to buy the micro-cube reflective squares for them, then the price difference would be a wash. The transmitter receiver would be a great choice, but not practical in this application, as the sensing - according to my design at least - needs to be done in the vertical plane, which would mean that I would need to string out the receiver along the garage floor, which means exposing cabling to the pressures associated with being treaded upon by humans, vehicles and lawnmowers, not to mention those pesky pets who like to "play" with those types of things. So I need something that emits/receives a beam or that can just sense objects without the need for such emission/reception. All options that I investigated for the latter design choice just didn't seem viable in the "real world" and that is how I arrived at the selection of the AB 42EF sensors. The basic plan here is to have sensors mounted in/on the garage ceiling. As the vehicle enters the garage, these sensors detect the vehicle's entry progression WRT vehicle position within the garage. Motion sensors emit too broad of a range for this to be a viable option, IMHO. I need to know exactly where the car is to within a greater degree of accuracy than a motion sensor can provide. This is another reason that the AB 42EF sensors seemed to be a better fit. Ok so you're probably wondering why in the heck I care to such a detailed degree. Well I had wanted to keep the wraps on things a bit until I had the project finished, but in the interest of implementing the best design ... this is a parking aid system. A bit of background seems appropriate. My mother had complained of difficulty in parking her Jeep in my garage when she came to visit. Furthermore she expressed a general concern/worry for not wanting to hit anything. So I mentioned the usual stuff, tennis ball on a string (which I didn't like), stop sign stand, etc. She seemed luke warm to those suggestions and so one day I made the mistake of saying "well then how about I just hang a traffic light in there for you, would THAT help?" To which she replied "oh you could do that? That would be wonderful!" .... oh boy ... I hadn't intended for that suggestion to be taken seriously. But too late now. And so the story went. After some investiagtion I learned about PLCs and I decided that I would prefer to use one in this implementation rather than to solve the problem "electrically" with relays and such. I learned ladder logix software in about 30 minutes and had my program designed, running and tested in about an hour. I've augmented it since then, but didn't need to make any fixes. Ladder Logix is kinda cool in a way, but the programming was rather easy really; it's been dealing with the hardware issues that has been the difficult aspect of this endeavor. Ok short version ... These sensors need to detect the vehicle entering the garage in reference to an exact point on the floor of that garage. Of particular importance is the sensor that will illuminate the red right, meaning to stop. This must be fairly precise, as it will govern the vehicle's ultimate position in the garage and should be exact enough such that she can close door behind her without worry that it will strike the back of her beloved Jeep. So in my estimation motion sensors just won't hack it. Also, I have developed a way to make the sensor adjustable so that different vehicles can be parked in the same spot, which furthers the need for precision and that complicates the notion of using diffusion type sensors due to the varying color of vehicles that could park there. Anyway. Sorry for the novel. That is what I am up against. The project has gone way over budget, but it's for my mother and if it gives her some ease of mind when she visits, then hey, all to the good. And I've learned something in the process, so ... Ok I'll stop now. Thank you for reading. Jerry

Hmmmmm .... well "no, not really" seems to be the answer I'm coming up with to your question. The target is not right-at floor level, no. What I am trying to sense is a vehicle entering the garage. So the height will depend on the vehicle in question, varing from just a foot or so (front end of sports car) to 6+ ft (top of SUV). If you know a fair amount about prox sensors, I'd like to learn more. Unfortunately all of the proxes that I researched (inductive) simply didn't have the range I needed, usually max-ing out at about 4 feet or so. I also looked into the diffuse option, but the AB representative told me that object color would play a factor in that scenario, as would general reflectivity of the object being sensed. Therefore I opted out of the diffuse stuff. I don't really like the reflective option because of the need to place a reflective material on the floor, but it seems (and that is the keyword 'seems') like the only really viable option in this application. And you're dead-on with the budget call, but heck, I blew that some time ago. Now it's either finish or else flush the money I've already spent and cannot recoup down the drain, which I am not inclined to do. Thank you for the continued feedback, I appreciate it! Jerry

johnboy -> Thank you for the feedback! Not sure what #1 is, if to be open, but a max of 9 ft seems a bit concerning to me, based on this experience. That is because it's right at the edge of the range I need and I wonder how well it would work at such range. One of the original thoughts that I had was to use a motion sensor, but all of the ones I found had too wide of a sensing area. I need something that is fairly pin-point in terms of accuracy and don't want a wide beam by the time that beam reaches 8.5 - 9 ft. And so I dismissed motion sensors relatively quickly. Good thoughts though! UPDATE: I returned the 42EF RightSight sensors today at the Reynco office, no problem. Need to purchase a different sensor now or else this project is dead. As I mentioned, I have been considering the AB Series 9000s. I decided to take a closer look at things just for fun, when... After doing a little more research I discovered the RightSight 42EF-XXXXX-XX sensor's laser cousin, the RightSight LaserSight 42EF-XXXXX-XX. These boast a larger margin and longer sensing distance than LED based sensors. Specifically the one I am considering is the 42EF-P8KBC-F4, which is essentially the same sensor "package" that I originally purchased, just using a laser instead of an LED. The RightSight LaserSight claims a maximum sensing distance of 15 m/49.2 ft, with a maximum spot size of only 16 x 20 mm at maximum distance. Much more what I need in this application. This particular model will also plug-right-into the 4-pin DC micro QD cordsets that I have, and of course the wiring is identical. It does have the teaching function and appears to be D.O. only, which is what I had the system to be configured anyway, which will save re-wiring. The two are priced similarly, with the 42EF RS LS being a couple of dollars more expensive per unit than the Series 9000. So I plan to call and speak with AB during the next couple of days while I research it a bit further prior to making a decision. I'd like to avoid having another go-around with this if possible, though again, I have learned a significant amount, which is always good. Anyway, I'll stop now. Keep you posted. Thanks! Jerry

Ok we have confirmation: these sensors just won't work in this application. The maximum range where I can establish both a recognized reflected light beam and have sufficient margin was at about 7 ft. Anything beyond that and I could barely get the sensor to find the reflected light, let alone a decent margin. And that is with a 5" x 5" reflective pad (there came a point where further enlargement didn't make sense and wouldn't work, but for the sake of completion I did it anyway). So this will set my project back several days, but on the positive side it has been a learning experience. I've discovered that I don't like sensors. Nah in all seriousness I knew at the outset that the achilles heal of this entire project would be the accuracy and reliability of the sensors. Without that, the remainder of this project is pretty much pointless. The sensors were and are the most vital component in the design. So it's back to the drawing board. On Monday I'll give my local AB distributor a call to see if I can stop by to return the RightSight sensors that I have and then pick up some of the Series 9000s. I'm in a suburb of Austin, the local distributor is The Reynolds Company and they just did an office move. Supposedly they'll be ready for business on Monday and I hope that proves to be the case. I'd like to finish things off and move on to some other projects that I have waiting in the wings. One of which is to work on this Ethernet adaptor stuff so that I can tweak the Micrologix program from the study if need be, as Bob suggested. And that will indeed be the case, as I just completed a re-wire of part of the panel tonight to include one more output (buzzer/flashing light). Naturally I need to add a couple of rungs to the program accordingly. So does anyone have any experience with the Series 9000s? Thanks!

Ok I played around with the sensors a bit this afternoon. And I don't have good news to report thus far. A bit of background: My sensors are photoelectric polarized retroflective, AB cat #42EF-P2MPB-F4. The reflective tape that I have is AB cat #92-99, so as it turns out I don't have the lowest reflectivity tape after all. This tape is advertised to be at 77% capacity of the "ideal" AB cat #92-39 reflective discs. Finally, I re-measured the floor-to-ceiling height and I remembered slightly incorrectly: it is actually 8' 3", not 8' 7", which should be to-the-better, albeit by only 4 inches. I digress. To conduct the testing, I created a reflector of my own in an attempt to replicate the size of AB #92-39 (3 in) by cutting the tape into strips, removing the backing tape and placing them on a piece of (flat) cardboard. I then connected one of the senors, taped it to the ceiling (temporary measure) and began playing around with the cardboard. At distances of about 5 feet or less, I could get good reception with acceptable margin. However at the longer distances I couldn't even establish reception. It was still daytime, so it was difficult to see where the laser beam was at the longer distances. Therefore I will try again tonight to see if I can make this work. It should be easier to spot and play around with the emitted laser beam at night. That said, I am not hopeful. I bought these particular model sensors at the suggestion of an AB representative who listened to my application plan and then made this recommendation. However the distance simply appears to be too great to affect a system with respectable reliability. As I mentioned, I am willing to give it one last try, but I suspect that I will have to make a run to the AB distributor on Monday during lunch and exchange these sensors for a different model. I think that the AB Series 9000 will be more suitable for this longer range application. They're a tad more expensive, but would seem to offer a degree of reliability that the RightSight sensors just cannot muster, at least not with the reflective tape, which is the only suitable reflector in this application. Will update again later tonight. Any feedback is appreciated. Thanks! Jerry

I have the sensor wired to operate dark (O.D.) so that the sensor will "close the switch" and send 24 volts to the PLC when the beam is broken. The program turns on a light. Or off, depending. Fell dead asleep last night after returning home from work. Long week and I spent several nights playing with this project until the wee-hours, so...will resume work today and update the thread with the findings of the experimentation. Thanks, Jerry