A Famous Question

[crying_baby]

Y DOES MY THIRD timer(THE VERY LAST 1) OOPS sry for the caps

y does my last timer count backwards instead of forward in my CW ladder?

i havent finish it yet but the very last counter got me busy and not to go on..

plz advice me is there something wrong on my ladder?

thank u for ur time and attention!!

my lader is as follow

¦PROGRM ¦TABLES ¦STATUS ¦       ¦       ¦       ¦SETUP  ¦FOLDER ¦UTILTY ¦PRINT

1insert 2edit   3modify 4search 5       6       7option 8goto   9more  10zoom

[     START OF PROGRAM LOGIC     ]

 START   STOP                                                           %M0002

--¦ +-----¦/+-----------------------------------------( )--

       ¦

%M0002 ¦

--¦ +--+

%M0002                                                                  SYST_ON

--¦ +------------------------------------------------( )--

 START  CPSENSR  STOP                                                   CAR_OK

--¦ +-----¦ +-----¦/+--------------------------------( )--

 START  CPSENSR  STOP   +-----+                                         %M0001

--¦ +-----¦ +-----¦/+---¦ONDTR+-------------------------------------------( )--

                        ¦0.10s¦

 STOP                   ¦     ¦

--¦ +-------------------¦R    ¦

       ¦                ¦     ¦

CPSENSR¦                ¦     ¦

--¦/+--+         CONST -¦PV   ¦

                 +00150 ¦     ¦

                        +-----+

                        %R0001

                        +00732

 STOP   CPSENSR %M0001  %M0006                                          SOAPWTR

--¦/+-----¦ +-----¦ +-----¦/+---------------------------------------------( )--

 STOP   CPSENSR SOAPWTR +-----+                                         %M0006

--¦/+-----¦ +-----¦ +---¦ONDTR+-------------------------------------------( )--

                        ¦0.10s¦

 STOP                   ¦     ¦

--¦ +-------------------¦R    ¦

                        ¦     ¦

                        ¦     ¦

                 CONST -¦PV   ¦

                 +00100 ¦     ¦

                        +-----+

                        %R0002

                        +00582

 STOP   %M0006  %M0006                                                  RINSWTR

--¦/+-----¦ +-----¦ +-----------------------------------------------------( )--

 STOP   CPSENSR RINSWTR +-----+                                         %M0006

--¦/+-----¦ +-----¦ +---¦ONDTR+-------------------------------------------( )--

                        ¦0.10s¦

 STOP                   ¦     ¦

--¦ +-------------------¦R    ¦

                        ¦     ¦

                        ¦     ¦

                 CONST -¦PV   ¦

                 +00060 ¦     ¦

                        %R0003

                        -15804

[      END OF PROGRAM LOGIC      ]

 

[Johnny T]

In S7 (I know you are not using S7, but I'm assuming it may be the same), when you go online to view an on-delay timer. It shows it counting down until it times out. The time it takes will still be correct, but its just the way the sofware illustrates it.

Looking at your code, it doesn't look like it matters whether the timer counts up or down as long as it takes the required amount of time to time-out.

If I've understood your question correctly, maybe this is the source of your confusion??

Cheers

JT

 

[Johnny T]

Just re-read this and your other question....

I didn't see the values below the timers before...

%R0001 = +732 %R0002 = +582 %R0003 = -15804

If %R0003 is holding an integer, is it possible that somewhere else in your code you have set the most significant bit of %R0003 ??

Have you tried a different address ie. %R0010 to see what happens?

Cheers

JT

 

[crying_baby]

thanks johnny, i'll chk it as i m at home now. but that makes sense too .

 

[Steve Bailey]

You have overlapped your timer registers. In the Series 90 PLCs, each timer takes three consecutive %R addresses. Your first timer actually uses %R001, %R002, and %R003. The second timer uses %R002, %R003, and %R004. The third timer uses %R003, %R004, and %R005. You can see that they are interfering with each other.

Change your second timer to %R004 and your third timer to %R007 and the problem will go away.

 

[crying_baby]

aww steve, thank u too
haf great day