[Remote access my PLC via VNC]

On 3/18/2015 at 6:16 AM, s.pratt said:

Hello,

Only if you are on the same network, you can connect to the unit by typing the IP address of the unit.

If you are outside the network, the only way I am aware of connecting to the unit is through a static IP address.  You may contact your cellular provider, or internet provider, to acquire more information on how to do this or how to get a static IP address.  Whoever is you internet provider may know of a better solution on how to connect to units on their modem.

There is more than one solution that provides remote network access independent of the public-facing IP address given by your ISP.  The product I use is an eWON Flexy.  In two weeks I will be in Texas to install Flexies at two remote sites.

[Fully self taught and looking for some advice/critique on my program.]

Hi Joe,

Nice post.  While generally avoided, I have used a sequence of (reset) coils connected in series.  Usually the situation is when I need to clear previous operating states on power up.  I will enable the rung with the first-scan contact.  And you are correct, I do not like it when the logic is so complex that the rung has to fold back on itself.  Often the logic can be rewritten using a couple of rungs, but sometimes it cannot be avoided.

I am sorry if the comment you quoted came across as unduly harsh.  I didn't mean it to apply specifically to Unitronics.  In my current project I have replaced a 15" PV with a UniStream because I liked what I saw: cost, capabilities, and customer support.  I was responding to another poster's post that because he didn't have intimate knowledge of how the ladder logic compiler worked, he couldn't trust how a given design would function.  As programmers, it is not our job to understand the internal workings of a compiler.  It is the job of the compiler designer to faithfully translate a ladder logic design into executable code.

Cheers.

[Fully self taught and looking for some advice/critique on my program.]

==> dB: Ask around and you will find that there are multiple ways of coding a valid solution.  You will also run into designers who express the opinion that to not do it their way constitutes at least poor if not "extremely poor" programming .  The more extreme the response, the more questionable the advice.

=> Ausman: Aren't you doing just that?

No, I am not.  I said that there are multiple valid solutions to a problem.  At this point I made no comment about anyone's specific code.

==> dB: Your rung 9 example above will work just fine but looks wonky.  I blame that on the software.  A rung should have only a single connection to the left-hand rail, and the software should not allow more that.  For that matter, it should allow only a single connection to the right-hand rail.

1. I said C_R_PLC's code is a valid, if unorthodox, solution.
2. I expressed my opinion that his style is not good practice and indeed should not be allowed by the software.
3. I agreed with Flex727's solution to rewrite the rung using a single connection point with the LH rail.

==> dB: Regarding the need for SB 1 on rung 26 in Flex727's example above, I would say that is is unnecessary.  If it turns out that without it the resulting logic does not perform as intended, that is a serious flaw in the software suite and if not addressed by Unitronics would cause me to look elsewhere for my PLC solutions.  I am confident that that is not necessary.

=> Ausman: So on one hand you are saying there should only be a single connection to the LH rail allowed by the software, yet when Flex does this the most practical way you complain about it????  And you also say rung 9 will work just fine, going against your advice?  Flex sugggested separating the rungs out but also offered alternatives.

=> Ausman: Discussion is welcomed on the forum, but nitpicking using conflicting statements within a post is not very helpful to anyone.

1. Your welcome is appreciated, but realize that meaningful discussion necessarily involves diverse opinions.
2. I wasn't nitpicking anything.  I said contact SB 1 was unnecessary; I did not say it was wrong.  This is called discussion.
3. I suggested a different, IMO better, way to code rung 9.  How is it going against my advice to acknowledge that the original method would work?  I am not afraid to say that someone else's style would work.
4. Yes, Flex offered an alternative solution., and I commented on it.  More discussion.
5. As explained above, there is no conflict in my original post.

By the way, I checked with seven different PLC programming suites I have used in the past, Unitronics being the latest one.  Three of them would allow a rung to make multiple connections to the left or right rail.  Four of them would allow only a single contact point.  I guess you know my preference.  ?

[Fully self taught and looking for some advice/critique on my program.]

On 8/16/2018 at 9:47 AM, C_R_PLC said:

I understand, thanks for taking the time to explain it. That whole notion of the compiler not necessarily doing what you expect it to never even crossed my mind. I just had the basic understanding that it read left to right and up to down, but even that's not really the compiler aspect of it.

Ask around and you will find that there are multiple ways of coding a valid solution.  You will also run into designers who express the opinion that to not do it their way constitutes at least poor if not "extremely poor" programming .  The more extreme the response, the more questionable the advice.

Your rung 9 example above will work just fine but looks wonky.  I blame that on the software.  A rung should have only a single connection to the left-hand rail, and the software should not allow more that.  For that matter, it should allow only a single connection to the right-hand rail.

Regarding the need for SB 1 on rung 26 in Flex727's example above, I would say that is is unnecessary.  If it turns out that without it the resulting logic does not perform as intended, that is a serious flaw in the software suite and if not addressed by Unitronics would cause me to look elsewhere for my PLC solutions.  I am confident that that is not necessary.