Jump to content
Paul11

Very Basic Ladder Logic Question

Recommended Posts

Hi,

I was a very basic ladder logic question. At the moment I can only force on outputs on from the  PLC . My latches do not seem to be working correctly. When I activate the start pushbutton when in online mode the  green light output is not activated. I know the output works when forced the output to a 1 the green light turns on. 

Sorry total new to PLC programming and just trying to get to a handle of it.

Any help at all would be great.

Thanks, 

 

image.png.1322a33cab85b3aa5b743b91a0e08b4e.png

 

image.png

Share this post


Link to post
Share on other sites

Do you have power flow all the way to the "Automode" coil when in online mode (i.e. are "Auto_Selector_5", "Stop_2_PB", "Emergency Stop" all closed and "F1_Overload" open)? Is "Start_1_PB closing?

Is this in a subroutine? If so, is it being called in the Main Routine?

Share this post


Link to post
Share on other sites
1 hour ago, Flex727 said:

Do you have power flow all the way to the "Automode" coil when in online mode (i.e. are "Auto_Selector_5", "Stop_2_PB", "Emergency Stop" all closed and "F1_Overload" open)? Is "Start_1_PB closing?

Is this in a subroutine? If so, is it being called in the Main Routine?

Hi, thanks for your help,

I have power all the way to the coil but it's not activating.  Should automode that is in parallel with start_pb be an internal bit or a output. I have it as a an global tag. It is the main routine.

Again thanks for the help,

Share this post


Link to post
Share on other sites

I should have the green light come on. At line two. It is energised right up to the coil but not the coil itself? Sorry the third line of code a duplicate of line one that was attached in error.

Share this post


Link to post
Share on other sites

Ya I'm sure they CPU is running. I can force on the all outputs but not through the code. I've even tried th code -Start pusbutton with  output green light. The green light is not operating. This is the way iv have entered my outputs?

image.png.c310f2226694965e65638f67272e805a.png

image.png.9e098cb02e178637bff6ff044c89af3f.png

Share this post


Link to post
Share on other sites

I'm not into Unistream at all, but is there an "Initialise and Reset" somewhere?  If none of the above in Flex and RobertU are true, perhaps it is something that simple...it is stuck on old info somehow.

cheers,

Aus

Share this post


Link to post
Share on other sites

Or if you have made lots of program changes with multiple down loads try downloading a blank program into the unit, reboot it and then put your program back in.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×