RSLogix Micro - Beginner Programming Thread

[fresh 1]

I hope this thread can help beginners learns the basics of PLC programming on the RSLogix Micro software (because its free). And I hope more experienced engineers can show us what we're doing wrong and the optimal way to program for these simulated real-world systems. So it's pretty simple, 1. Post a graphical representation and text description of the automation process to be performed 2. Post your PLC program written in RSlogix Micro. --------------------------------------------------------------------------------------------------------------------------------------------- Here's a simple mixing tank. RSLogix program. MixingTank.RSS When the RUN switch is activated Pump1 and Pump2 turn ON as long as the tanks are not full, when the tanks become full limit switch 1 and 3 close and turn off the Pumps. Then (spring-return) solenoid Valves 1 and 2 open and release the contents of both tanks into the mixing tank, A timer keep liquid there for 120 seconds, then empties the mixing tank by opening Valve 3 until the empty sensor stops it. Program repeats cycle. This is the the first program I've written so probably not correct, Any help is greatly appreciated. Other beginners like me feel free to post your programs in this thread and we can learn from each other. Thanks! Edited 3 Oct 2010 by fresh

[OkiePC 13]

Nice first post! I opened your program and noticed the first rung is incomplete. Perhaps you uploaded the attachment before saving your work? There's nothing to make use of the "run" and "stop" inputs. There are no conditions to start/reset the mix timer. For a simple sequence, I recommend using internal mutually exclusive bits to keep track of the "state" of the machine, and those bits can then drive your outputs. I took the time to write you an example, using your I/O as a start. I noticed you had a symbol name for ouput 5 that I believe is supposed to be an input so I changed that, and incorporated several basic methods in the revision that should give you some things to think about. MIXINGTANK2.RSS Edited 3 Oct 2010 by OkiePC

[b_carlton 60]

OkiePC did a great job showing an example of a structured program based on your input. Another example of items he addressed: in rung 1 of your program think of what will happen as tank 1 is being emptied into the mixer tank. The 'Tank Full' switch will no longer indicate full and Pump 1 will turn on even while the tank is trying to empty. In rung 3, the Tank Full switch turning off will close the emptying valve until the tank reaches full again then it will start over. In other words Tank 1 (and Tank 2 in the same manner) will never empty fully. It will just keep emptying slightly until the Full switch releases then start filling again until the Full switch is made. A rather interesting version of an oscillator but probably not what you wanted. OkiePC shows that the program must be divided into steps. Each step embodies one of your 'do that until this happens' statements. The 'until this happens' is the trigger to stop doing this step and start doing the next. There are a number of ways to do this and OkiePC shows one excellent way. Have a great time with PLCs.

[Dennis 0]

OkiePC I am fairly new to plc programming and was wondering how the 1 state change per scan bit works I can see it gets latched but not unlatched. is it similiar to using the one shot bit? Ive attatched my first two programs that i have wrote for equipment I built. I know there not as good as they could be but they work. I tried to post a video but it wouldnt let me Thanks to all who share thier knowledge with us you guys are great PICK AND PLACE VER 8.RSS COUNTING CONVEYORver3.RSS

[OkiePC 13]

That bit is part of the word that gets cleared each time a step transition occurs, so it will only go "off" for the rest of that scan, and gets latched again before the step transition logic. It is one of those things that is not always used, but often handy.

[fresh 1]

OkiePC, just wanted to say Thanks for re-writing that mixing tank program. I will study it carefully. bcarlton, I see what your saying about the oscillation-type flow in the original program.

[OkiePC 13]

You're welcome, Dennis. Keeping coming back here and to plctalk.net Another tip for streamlining your ladders attached... fixing_wedding cakes.zip

[Dennis 0]

Thats a great tip I could never figure out how to do that I end up with alot of wedding cakes thanks alot

[Theo 0]

Greetings I am new here and have some experiencs with old GE fanucs and a Couple lines of the allen bradley family as well as some of the cheap micro controllers. I just got slated to head up a project where I work, a small plastic extrusion company to design and install a scada system for 4 water tank level and temperatures and 3 gearbox temperatures 3 points each gear box. I have selected j type termocouples and will be using the micrologix 1400 I have all of the plc parts on order. My main first question is if I start writing the program in the rsmicro starter can I open it in micro logix deveolper and change the configuration to the 1400? Thanks In Advance Edited 30 Dec 2010 by Theo

[b_carlton 60]

Yes, you can start targeting a Micrologix 1100 in the Lite (free) software. Save the program. It will be an RSS file. You will then be able to open it in the full version and change the processor to a 1400. Of course you won't be able to go back if you use any capabilities that the 1400 has and the 110 doesn't. But at least you can start.

[BobLfoot 122]

I really Like the idea of this thread. 1. Here is my picture of the process. 2. Here's what the process must do. A. It's a simple two into one merge - boxes from conv 200 and boxes from conv 300 feed onto conv 100. B. CONV 100, CONV 201 and CONV 301 are roller conveyor and can accumulate boxes - The have a release stop at the end with PE100, PE201 and PE301 - not otherwise shown. C. CONV 200 and CONV 300 are two part metering belt conveyors which will pull a gap between the boxes released from CONV 201 and CONV 301 respectively. D. The Stopper at PE 100 will release boxes for 30 seconds each time the release boxes pb is pushed. E. If PE 101 is blocked for ten seconds the feeding of boxes is stopped until it clears for 30 seconds. F. Boxes reaching PE 200 and PE 300 are taken on a first come first serve basis. - You must make sure you sent the whole box and not two boxes { no box is longer than 5 seconds}. G. Belts CONV 200 and CONV 300 run if PE 200 or PE 300 respectively is not blocked, otherwise they run only when feeding the merge on their turn. H. CONV 201 and CONV 301 are running all the time as they are accumulating roller conveyor. I. The Stopper at PE 201 and PE 301 only drops if CONV 200 or CONV 300 is running and then only for five seconds max or while the PE is blocked. J. If PE 202 or PE 302 becomes blocked for 10 seconds then that side is max full. Suspend the normal merge rules and take boxes from that side for one minute. After the minute resume normal merging. If the other side goes full during the minute don't cut your minute short jsut give it a minute after this side is done. 3. I'm not posting my program yet cause I'm hardly a beginner. This was a test exercise for me some yesrs ago and I leanred a lot. Good Luck All. BEWARE THIS LOOKS AND SOUNDS SIMPLE BUT TO GET A WORKING VERSION IS ANYTHING BUT.

[Theo 0]

Okay I spent all afternoon trying to figure out what is probably a very simple task and came up up dry. I have 4 rungs each with an XIC followed by a debounce timer as these will be float switches. now to where I am stumped. I want to do two things with this, First I want connect each of the timers to one output for a General tank water lvl alarm lamp. The other thing a want to accomplish is to put each of the four rungs onto seperate outputs to drive an HMI showing which tank is alarming. I have tried to bring a vertical run after the timers to nest all of the timers and cannot figure out if that is possible. I was wondering if it would be possible and or easier to add a new rung using the outputs of the existing tanks and debounce timers as logic to a new output to drive the general tank alarm. Any advise would be appreciated. Theo Inline PLC.RSS

[b_carlton 60]

I took your program and did some modifications. Maybe it will get you going. 1. I assigned your input switches to actual input positions. 2. I assigned your timers to actual timers in the database. I changed the preset from 0 to 1 (one second) 3. I removed the illegal extensions that were to the right of the timers. Timers are always at the far right side of the rung. 4. From each timer I used its DONE bit (DN) to trigger a light, assigned to a real output. 5. I added a final rung showing how conditions can be combined. In parallel they become an OR, any one on turns on the output. If you have any questions please re-post. INLINE PLC.RSS

[Theo 0]

Thanks that was a great help

[COOP 0]

This thread looks like it could be both fun and educational so though I'd have a go at it. I was unable to open the files in post 1 & 2 the files in post 4 opened just fine. I think it's probable an issue with the old version of RS 500 starter that I'm using, 7.10.00. So hears my attempt at the mixing tank. MIXINGTK.RSS I think I'll make an attempt at Bob L's conveyor, It's looks way beyond my pay grade, just reading the description of the process leaves me scratching my head.

[Marco_Polo 0]

Hy Guys! I am trying to create a program for tank temperature and level control. Also I would like to control temperature by PID. I don’t have any experience in ladder programming so any kind of help would be welcome. Thanks. Pump IN is turned on by the low-level for along as tank is not full. When the tank become full, high-level will turn off the pump IN. If there is low temperature reading from temperature sensor, the heater will be turned ON, a long as temperature in tank doesn’t reach desired value. When the liquid in tank reach desired temperature, and tank is full the pump OUT will be turned on. Pump OUT will be turned on until liquid level e doesn’t decrease to the low-level value. TEMPERATURE AND LEVEL CONTROL_BAK001.RSS Edited 6 Jul 2011 by Marco_Polo

[Mickey 51]

Rung zero turns the heater on but what shuts it off? ( think High temp) Rung one turns the pump_in on but what shuts it off? ( think high level) Rung two turns the pump_out on on high level but what keeps it running until it reaches low level? ( think latch) What type of temperature sensor do you have? Edited 6 Jul 2011 by Mickey

[Marco_Polo 0]

Thank you Mickey! Well I thought that the pump IN will be turned.off when examine if open (HIGH_LEVEL) became false in the rung 0. I realize now that I was wrong. Like I said in my earlier post I don't have any experience with ladder programming. Only experience that I have is Simulink in Matlab, that is similar to function block diagram. So this program what I am trying to create is only theoretically example how tank control could be done. Thank you for your help.

[DATAfiend 0]

Hi guys. I hope I don't hi-jack this thread. I have the RSLogix Micro Starter Lite edition (8.1.0).I've downloaded several of the examples on this thread but the error about "unsupported processor" typekeeps popping up. I chosen all of the different ones, "Micrologis 1100 series b, series a, Micrologix 1000" None work. Am I missing something with my version? I know people on this site always mention drivers for communications, but I don't need that at this point. Thanks

[plcnovice61 0]

Data, have you got to see the code yet? l have downloaded a copy of lite version to confirm operation and opened the projects. It works as it should. Have you downloaded one of the projects then when Micro software is open, go file/open-then point to downloaded project. You don't need to do anything else.