Help with this program

[shawn k]

1. Program a single timer (TMR) such that:
a. when switch 1 is on, there is a 1 sec delay, then LED 6 turns ON
b. when switch 2 is on, there is a 3 sec delay, then LED 6 turns ON
c. when switch 3 is on, there is a 5 sec delay, then LED 6 turns ON
2. Program two Shift Registers(SR) and one timer(TMR) enabled by switch 4
a. The 1st SR will turn the lights ON with the following timing (REMEMBER YOU CAN ONLY USE 1 TMR for part 2):
i. LED 1, immediately
ii. LED 2, after 2 sec.
iii. LED 3, after 4 sec.
iv. LED 4, after 3 sec.
b. Pause for 4 seconds, then turn the lights off using the second SR in reverse order (4, 3, 2, 1) with a 4 sec pause between the lights turning off, pause one second and go forward again. (REMEMBER YOU CAN ONLY USE 1 TMR FOR BOTH SR’s in part 2)
c. The process should work indefinitely.

[milldrone]

shawn,

A couple of questions

Originally Posted by shawn k

1. Program a single timer (TMR) such that:
a. when switch 1 is on, there is a 1 sec delay, then LED 6 turns ON
b. when switch 2 is on, there is a 3 sec delay, then LED 6 turns ON
c. when switch 3 is on, there is a 5 sec delay, then LED 6 turns ON

What do you want to happen if more than one switch is on?


Concerning the shift register part of the program Do you have to use two shift registers? Can you use just one? Do you have to use a timer at all?

When you were just a little tyke. Did the neighbor girl next door ever take you behind the woodshed and tell you "Ill show you mine if you show me yours first"?

Originally Posted by shawn k

2. Program two Shift Registers(SR) and one timer(TMR) enabled by switch 4
a. The 1st SR will turn the lights ON with the following timing (REMEMBER YOU CAN ONLY USE 1 TMR for part 2):
i. LED 1, immediately
ii. LED 2, after 2 sec.
iii. LED 3, after 4 sec.
iv. LED 4, after 3 sec.
b. Pause for 4 seconds, then turn the lights off using the second SR in reverse order (4, 3, 2, 1) with a 4 sec pause between the lights turning off, pause one second and go forward again. (REMEMBER YOU CAN ONLY USE 1 TMR FOR BOTH SR’s in part 2)
c. The process should work indefinitely.

Seriously, show us what you have.

[milldrone]

Originally Posted by shawn k

b. Pause for 4 seconds, then turn the lights off

I'm with you, up to this point

Originally Posted by shawn k

with a 4 sec pause between the lights turning off, pause one second and go forward again.

I cannot figure out what you mean by this statement. Why not just say a 5 second pause?

Here is a 64 dollar question. Is there a particular reason you need to use a shift register? A drum would be very simple to implement.

[milldrone]

Originally Posted by milldrone

A drum would be very simple to implement.

See attachment.

[Tinker]

Originally Posted by milldrone

I'm with you, up to this point

I cannot figure out what you mean by this statement. Why not just say a 5 second pause?

I think he means that there is a 4 second delay between led2 turning off and led1 tunrning off then a 1 second delay before section a. repeats, wehere led1 will turn back on:

4 sec pause between the lights turning off, pause one second and go forward again
(forward again) a. The 1st SR will turn the lights ON with the following timing (REMEMBER YOU CAN ONLY USE 1 TMR for part 2):
i. LED 1, immediately

Originally Posted by milldrone

Here is a 64 dollar question. Is there a particular reason you need to use a shift register? A drum would be very simple to implement.

I suspect that the shift register is his homework asignement, maybe next week he'll want a drum


""I'll show you mine if you show me yours first"

I used to answer questions on Yahhoo answers, and it was not all that unusual to see a homework question where someone said they had already worked out the problem themselves but they wanted to see someone elses answer for confirmation, while I usualy ingnored such questions, once in a while I'd sugest they post their answer and then I'd tell them if they got it right, but all that ever got me was a "thumbs down" and nobody ever botherd to show their answer. The funny thing is i decided to Google "1. Program a single timer (TMR) such that:" and guess what was the second item in the search results: http://answers.yahoo.com/question/index?qid=20091103142944AA1vseC"

Unfoutunatly I not familaiar with Directsoft (and on the Yahoo post he said DL06), I don't even know if there is any standard for for a PLC "psudo code". Still, here is one Idea I had for the first part:

1. Program a single timer (TMR) such that:
a. when switch 1 is on, there is a 1 sec delay, then LED 6 turns ON
b. when switch 2 is on, there is a 3 sec delay, then LED 6 turns ON
c. when switch 3 is on, there is a 5 sec delay, then LED 6 turns ON

if S1 or S2 or S3 -> enable timer1, interval seconds, set point 5
(if your timers count in say intervals of 100ms multiply my constants by 10, if 10ms, then * 100)
if S1 and timer1 current value = 1 -> set LED6
if S2 and timer1 current vlaue = 3 -> set LED6
if S3 and timer1 -> set LED6 (actualy the S3 is redundant here, if the timer is running and the LED is not on by now, S3 must be on)
if (not S1) and (not S2) and (not S3) -> reset LED6 (and timer1 if turning off it's enabling inputs doesn't reset it, i.e. a maintained timer)

In this case if more than one switch is closed the LED will turn on at the shortest interval selected. There is one interesting "feature" if S3 is turned on, then after more than 1 and less than 5 seconds S1 is turned on and S3 turned off (in that order) the LED will not come on even though a switch is on !, using "equals or greater than" or eliminating the "redundant" S3 in the the next to last rung would eliminate that, but that wouldn't be as much fun.

Since the details coding a shift register could be implementation dependant I'm not going to try to tackle that one in any detail, but it seems to me that one would have to program the one allowed timer as a 1 second pulse generator that clocks the SR and get the other time intervals by where you get the data out of the SR.
It seems to me too that it would be simpler to use one shift register (or a drum), but again, I think this is home work not real life.

[milldrone]

Originally Posted by Tinker

""I'll show you mine if you show me yours first"

I was just trying to add some humor instead of of ranting about homework.

Originally Posted by Tinker

I suspect that the shift register is his homework asignement, maybe next week he'll want a drum

I suspected this from the beginning. Thats why I responded with an answer that was usable in the industrial world, but not for his homework. I had also considered giving him the monics for the code I wrote, and stripping out everything but the rung comments.

If he were to respond I will try to lead him in the right direction. But I will not give him the answer outright.

[Tubecut]

Well, I was usually the one that suggested the "show me scenario "