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September 25, 2017, 11:53:27 am


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 1 
 on: Today at 11:45:03 am 
Started by mhw - Last post by Controls Guy
I used a OFFDTMR for the first time the other day. If the off delay time is set to 0 the output will never be true.

I've used like 5 off delay timers in 3 decades or so of doing this stuff.  The rules on off delays vary from brand to brand. So the first solution to come to mind is invariably writing the rung logic inverted (or adding a NOT contact inline) and using a normal on delay timer.

Now it occurs to me that I need to check and make sure TMR's work correctly with a zero setpoint.

 2 
 on: Today at 10:36:00 am 
Started by mhw - Last post by Evilbeard
Hmmmm. I have several of these in the field right now...
I need to dig through some code to see what is going to happen if someone changes the settings to zero.
I would expect the output to always be true when the input leg is true, regardless of the time setting.

That's what I expected to see. Here's what X0 driving timer T0 (set to output Y0) does with an off delay set at 0.


 3 
 on: Today at 10:29:30 am 
Started by mhw - Last post by plcnut
Hmmmm. I have several of these in the field right now...
I need to dig through some code to see what is going to happen if someone changes the settings to zero.
I would expect the output to always be true when the input leg is true, regardless of the time setting.

 4 
 on: Today at 10:21:04 am 
Started by mhw - Last post by Evilbeard
Mixed emotions about that. I can perhaps see the merit in it turning on for one scan, but then the time wouldn't actually be zero. I would considering it to be working as designed though.

I can see what he's saying. If you put the off delay to 0, the output never goes active. It should toggle on/off with the input. It's just always false. The .done bit is always on, so the Output is always off.



In order to make it operate like it "should", you have to use logic like this:


 5 
 on: Today at 09:25:32 am 
Started by mhw - Last post by mhw
Quote
True, but if your off delay time is 0, why do you need an off delay timer to start with?
The customer wanted a variable to delay the off. Sometimes that variable will be 0.
Quote
Mixed emotions about that. I can perhaps see the merit in it turning on for one scan, but then the time wouldn't actually be zero.
The logic diagram shows the output being true when the input leg is true.

 6 
 on: Today at 09:01:33 am 
Started by mhw - Last post by BobO
Mixed emotions about that. I can perhaps see the merit in it turning on for one scan, but then the time wouldn't actually be zero. I would considering it to be working as designed though.

 7 
 on: Today at 08:39:54 am 
Started by mhw - Last post by Evilbeard
I used a OFFDTMR for the first time the other day. If the off delay time is set to 0 the output will never be true.

True, but if your off delay time is 0, why do you need an off delay timer to start with?

 8 
 on: Today at 06:07:44 am 
Started by mhw - Last post by mhw
I used a OFFDTMR for the first time the other day. If the off delay time is set to 0 the output will never be true.

 9 
 on: Today at 05:57:03 am 
Started by BobO - Last post by franji1
Open DMD. The file can be found in the Launchpad under the applications tab.

Yes!

The original file is in the Windows folder, however...

Due to security reasons, the OS keeps the actual modifiable copy  in an invisible folder structure under your user account.  The "DmDesigner.ini" entry in the Launchpad's Applications group is a batch file to locate that actual file and load it in Notepad automagically so you can modify it.

 The one in Windows is just a placeholder for the OS but is not used by the executable.

 10 
 on: Today at 05:41:01 am 
Started by BobO - Last post by mhw
Open DMD. The file can be found in the Launchpad under the applications tab.

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