HMI Display

[Anu]

Hi, 

 

I am using a V120-22-T38. I have about 9 timers in my program. When I download the program to the PLC and run it, I see the timers running (via the "watch online" feature). But the timers don't show up on the HMI display the first time. Once the timer elapses, it then shows up. If I hit run the second time, the timer runs again in the PC, but no change on the HMI. 

 

Any idea what could possibly be wrong? 

 

Thank you!

-Anu

[Alexander]

Hello Anu,

 

When creating a timer on the HMI there are a couple of options on how the timer will be displayed. By default the timer HMI element will display current remaining time and it will decrement down to 0 while running. There is also an option to display the preset time which would cause the value to remain at the static preset.

 

I would recommend checking this setting to verify that it is set to current remaining time, and that it is linked to the timer you are viewing in online mode.

[Anu]

Thank you for the quick reply. 

 

I did check for that before my post. It looks correct. More over, I ran each subroutine separately. The timers are showing up alright. This happens when I run the subroutines together (4 of them). I am using separate bits for each timer. So they are not interfering with each other too. 

[Alexander]

Is it the current value that is not displaying on the HMI, or something else? As long as the specific timer being displayed is being called within the logic it should absolutely count down from the initial value to 0.

 

Would it be possible to attach the program for a more detailed review? If this is possible please describe which timer is not working properly and where it can be found within the logic.

[Anu]

Hi, 

 

Attached is my .vlp file. 

 

First cycle - Valves open; 20 seconds later pump comes on

Second cycle - Valves shut; wait for 45 seconds (I am calling it reset all); Two valves open; One valve shuts after 20 seconds; The second one shuts after a minute

Third cycle - reset all; A set of valves open; pump switches on in 20 seconds; entire cycle runs for 5 minutes

Fourth cycle - reset all; A set of valves open; pump switches on in 20 seconds; entire cycle runs for 5 minutes 

 

For saving time, I have used 15 secs (instead of 45 secs for reset all)

2 secs for 20 seconds

5 secs for 5 minute timer 

 

All I see when i execute the program is my first 20 second timer (when the pump comes on). None of the other timers function on screen but they are doing what they are supposed to do (when I see the timers portion through the watch online mode). 

 

Hope I explained it well. 

 

Thank you

-AnuAll_Cycles_Manual_Test.vlp

[Alexander]

Anu,

 

After reviewing your program I found that you are calling each HMI display every scan that one of the cycles is running. Since the display is being called every scan this will cause the variables to not fully load.

 

To correct this you only need change the logic to only call the screen once at a time. One solution for this is to change all of the contacts linked to key system bits (SB 41, 42, 43, etc) to positive transitions and call the screen within the same net. This will then call the HMI display only once and the rest of the logic should work exactly the same.

 

Please let me know if this solution solves this problem.

[Anu]

Yessssss!!! 

 

Fixed it! 

 

Thank you!! 

 

-Anu