PLC Ladder Help 4 A newbie

[dlp154]

when writting a program and you have concerns about wheather or not a certain function in the real world is working or not i find that if you make the input prove itself by using the inverse operation in another rung you are assured your system is pretty fool proof it means alittle more thought but after all isn't this why we use a plc?

 

[trawets]

Wow Thanks pretty much taken the wind out of my sail.
Seriously though can fully understand what you mean
just trying to do it by stages, add as i go along ,took me 2 hrs 4 that go, having probs trying to work out the delay for fan shut down,
can work it out 4 both M/c stop, but what if only using 1/Mc?

Hey thanks so much! really enjoy talking to those who know !

 

[trawets]

Seem to be stuck on how to progress
This ladder seem to sort of work but I feel that I am not quite there
have added stop bits to the diagram but not happy with the delays
would grately appreciate some pointers.
0,Start_Fan
1,Stop_Fan
2,Fan_O_L
3,M_c1_O_L
4,M_c2_O_L
5,Start_M_c1
6,Start_M_c2
7,Stop_M_c1_
8,Stop_M_c2
9,all_Stop
Sorry dont know how to insert the ladder

 

[Allen Nelson]

From trawets

I know im takking a bit of a liberty sending you this email, for which i
apologise I just seem to hitting dead ends.
The soft ware I was using wuoldn't allow more than 8 inputs. Now using TriLoOGI
but cant seem to export to a readable file, and wont give me a statement list.
Any suggestions
sorry for being a pain
Very best regards
Stewart

Stewart:
Don't worry about it - youre not being a pain. Solving problems is what this forum is about.

Unfortunately, I don't know the software, and am no expert on the hardware, so I'm afraid I can't help you. But I'm posting your question here, so someone else can.

Have you looked at the hardware you are using? Does it physically allow for more than 8 inputs? (Some smaller PLCs are limited in the number of ins and outs they can handle). Sometimes the software is smarter than us people-types in knowing the limits of what can be done.

If that's your limitation, then you'll need to rethink your control strategy. Perhaps a single button to control each machine (press once to start, again to stop). There's plenty of code (good and bad) on this forum for how to do that - search for "FLIP FLIP*" or perhaps "TOGGLE".

 

[trawets]

Hi Guys
Have put together a program
Dont think this one is too far away,pretty much the same as the last one but have added the extra bits that was suggested.
Would be grateful if someone would run a critical eye over it before I submit the excercise.
Sorry but its still only in statement list
Used Medoc 2.1 dos wont give me a ladder copy.

STR X0 Fan_on PLS M3 Fan_ON

STR M3 Fan_ON
ANDN X6 Stop_Fan
ANDN X9 All_Stop
ANDN X3 Fan_O/L
SET M0 MCR

STR M0 MCR
ANDN X3 FanO/L
ANDN X9 All_Stop
OUT Y0 Fan

STR M0 MCR
ANDN X9 All_Stop
TMR T0 K200 M/c_Enable

STRN X2 M/c2_Start
OR T1 Wait
AND M0 MCR
AND T0 M/c Enable
AND X1 Start_M/c1
ANDN X3 FanO/L
ANDN X4 M/c1O/L
ANDN X9 All_Stop
ANDN X7 M/C1 Stop
OUT Y1 M/c_1

STR X1 Start_M/c1
SET M1 M/c_1_CR

STR M0
STR M1
OR M2
ANDSTR
TMR T1 K100 Wait

STR X1 M/c1_Start
OR T1 Wait
AND M0 MCR
AND T0 Enable
AND X2 Start_M/c2
ANDN X3 Fan_O/L
ANDN X5 M/c2O/L
ANDN X8 M/c2_Stop
ANDN X9 All_Stop
OUT Y2 M/c_2


STR X2 M/c2_Start
SET M2 M/c_2_CR

STR M0 MCR
AND X7 Stop_M/c1
AND X8 Stop_M/c2
TMR T2 K200 Fan_Stop_Delay

STR X7 M/c1_Stop
OR X3 Fan_O/L
OR X4 M/c1_O/L
OR X9 All_Stop
RST M1 Reset_M/cCR

STR X8 M/c2_Stop
OR X3 Fan_O/L
OR X5 M/c2_O/L
OR X9 All_Stop
RST M2 Reset_M/c2CR

STR T2
OR X3 Fan_O/L
OR X9 All_Stop
OR X6 Stop_Fan
RST M0 MCR

END

Inputs Outputs Timers
Address Label Address Label Address Label/Value

X0 Fan_ON Y0 Fan T0 Enable(K200)
X1 M/c1_Start Y1 M/c_1 T1 Wait(K100)
X2 M/c2_Start Y2 M/c_2 T2 Fan_Stop_Delay
X3 Fan_O/L
X4 M/c1_O/L
X5 M/c2_O/L
X6 Stop_Fan Control Relays Label
X7 M/c1_Stop Address
X8 M/c2_Stop M0 MCR(Master)
X9 All_Stop M1 M/c_1_CR
M2 M/c_2_CR

 

[trawets]

Allocation Table went to pot had it in a nice table
Here itInputs
Address Label
X0 Fan_ON
X1 M/c1_Start
X2 M/c2_Start
X3 Fan_O/L
X4 M/c1_O/L
X5 M/c2_O/L
X6 Stop_Fan
X7 M/c1_Stop
X8 M/c2_Stop
X9 All_Stop
Control Relays Label

M0 MCR(Master)
M1 M/c_1_CR
M2 M/c_2_CR
Outputs
Address Label
Y0 Fan
Y1 M/c_1
Y2 M/c_2
Timers
Address Label/Value
T0 Enable(K200)
T1 Wait(K100)
T2 Fan_Stop_Delay
is in a list