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-   -   How does a 4-level elevator work in a SFC ? (

JungleKidd January 2nd, 2018 10:49 AM

How does a 4-level elevator work in a SFC ?
Hello, I'm trying to make a 4-level elevator work in SFC, but I feel kinda lost. Could anybody help me with at least the first 2 level SFC? Thank you

gclshortt January 2nd, 2018 03:30 PM

The above link may help you out with the logic. The flowchart may be helpful to you.

PLCnovice61 January 3rd, 2018 02:00 PM

lf you go in downloads (Allen Bradely and maybe in others)on the tool bar above there are some examples, for elevators (LogicPro simulator code). They are most probable in ladder, but it will give you some idea of the code required.
But please note, that unless it was written by by Lance01, DO NOTE take it for granted that it will work as it should.

RussB January 3rd, 2018 02:40 PM

Q: How does 4 level elevator work in SFC?
A: Just like it will when properly hard wired.

shooter January 4th, 2018 01:03 PM

Make a start sequence, like close doors etc.
then a split in four buttons, so you will get 4 separate programs for each button.
below them, move the cab to the wanted position, below open the doors and wait
loop back to above, and wait until a button is pressed.

show please what you have made.

RocketTester January 4th, 2018 02:19 PM

Selamat. Isteriku dari Indonesia, dan saya jalan di Ambon, Komodo, Bali dan Jakarta di Agustus 2017.

I don't think you can program it solely in SFC. SFC allows designing an overall logic flow (based upon input conditions), but I don't think it allows setting outputs. For that, you must put other PLC code within each SFC block, which can be ST, LD, FBD, or CFC, and you can use different type code in each SFC block.

kalabdel January 5th, 2018 12:03 PM

Slightly off topic. I was at the ground floor of a building and wanted to go to the second floor. There were four elevators and no buttons so I kept looking around and found a screen on the wall beside the first elevator. It had numbers on it so I touched number 2 and a few seconds later an elevator door opens up and a female announcer came on but I didn't pay attention till I got in the elevator. It said something like "ground floor going to third" and a screen inside the elevator displayed the number 3. So I wondered out loud why is it going to 3 when I clicked 2 and there were no button on the screen to touch and no physical buttons in the elevators so I could only get off at floor 3.
As you must've experienced or figured out, the elevator takes it assignment from the ground floor screen and I got in the wrong elevator that assigned to someone else who selected the 3rd floor. I was supposed to pay attention to the announcement and I think there was also a display above the elevator, not entirely sure. But until I spend more time playing with it I have to say it is typically crappy/ridged system that I encounter more and more as more tasks are being automated. Life is going to get very difficult for the next 20 years or so.

RocketTester January 5th, 2018 12:21 PM

To go further off topic (on a Friday),

Kalabdel's experience could be a programming glitch where the selection (floor 2) counts from 0 and actual destination (floor 3) counts from 1, though wonder how that could slip thru testing. I have seen commercial software which mixes that up, particularly in error messages. At least the system didn't force you to watch advertisements, as done in the U.S. with a captive audience at gas pumps and urinals. Some genius might go even further and make the elevator go slow to force the captives to watch the full ad. Marketers are getting desperate since people record TV shows to skip ads, learned to ignore the first paid Google search returns, and filter out ads slipped among Facebook posts.

BTW, when I program, I usually count array indices from 1, to match physical channels 1,2,... Microsoft mandated in .net that array indices count from 0 (in VB6, one could define). I still loop arrays from 1 (as humans count). I sometimes use the 0th element to store "meta info" about the array.

kalabdel January 5th, 2018 01:06 PM

Now that you mention it, when the way down there were two choices G and GR and I had to think a for a bit as to which is ground (because I have lots of time, patience and the mental clarity to spend on such things) and I clicked "G" and "ground floor" was announce which turned out to be the floor I wanted. I have no clue what GR stands.

bernie_carlton January 5th, 2018 01:18 PM


kalabdel January 5th, 2018 01:24 PM

Very possible. I guest the days of P1,P2.... are gone. Welcome GR :D

harryting January 5th, 2018 01:42 PM

Ya, I ran into one of those system in DT Seattle, pretty cool.

RonJohn January 5th, 2018 01:53 PM

Still holding out for one of these myself.

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