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Timer (TP, TON) dont work - when I insert FB1 into FB2 like template

Created by: Bill1777 at: 10/13/2013 10:47 PM (10 Replies)

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10/13/2013 10:47 PM	Rate (0)
Bill1777 Bronze Member Joined: 4/30/2011 Last visit: 1/9/2022 Posts: 223 Rating: (4)	Timer in FB2 (TP, TON) dont work - when I insert FB2 into FB1 (like template) ?!!! Attachment 3 copy.jpg (779 Downloads)

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10/13/2013 11:11 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/24/2025 Posts: 15558 Rating: (2468)	Timers only time when the fb is enabled. Pass the NO contact as an input to the block and control logic within the block accordingly. Just keep the timers timing.
	science guy
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10/14/2013 10:52 AM	Rate (0)
Bill1777 Bronze Member Joined: 4/30/2011 Last visit: 1/9/2022 Posts: 223 Rating: (4)	Tks of coursefb2 is enabled ButTP, TON - dont work inside FB2 ?! Attachment 4.jpg (747 Downloads)
	Last edited by: AndyNeva at: 10/14/2013 10:54 AM
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10/14/2013 2:56 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/24/2025 Posts: 15558 Rating: (2468)	AndyNeva Tks of coursefb2 is enabled ButTP, TON - dont work inside FB2 ?! In your posted image, FB1 was enabled and running but FB2 Q8.0 was off. Then in FB2, it shows enabled. In any case, I tested your logic in V12 SP1 Update 2 and it works just fine. Once I turned on #consumer in FB2, TP produced a 2.5s ON pulse, which enabled TON which timed for 2s and turned on it's Q output for 0.5 seconds - once the TP 2.5s is up, it turns off the output.
	science guy
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11/18/2013 3:18 PM	Rate (0)
Frederik Posts: 23 Rating: (1)	Came across this thread and wanted to know if you ended up finding the cause for your problem. I am also having problems with TON timer not working with TIA, but I am using PLCSIM. Basically I use a temporary bit (M400.0) to enable the timer (say "MyTimer" in DB13). I useT#15000ms as PT directly assigned on the TON call, and no matter what I do with M400.0 the timer will not start timing (ET stays at 0ms). The timers used to work earlier today but now for some reason they wont. That was after I tried to pass"MyTimer".PT to the PT parameter on the block call. I know it sounds redundant but as we are not allowed to leave PT unassigned, I wanted to see if that would have the effect as not passing any variable, like we can do with FBs, and leave the PT variable free to assign in the program. Of course I removed that and am now trying to make it work with a direct assignation of T#15000ms at PT. I am at the point that the program is completely bypassed and only the timer is being called in OB1, so as to avoid any errors on my part but still no change. Tried to shutdown PLCSIM and start a new simulation project and download, also tried to create a new TON call with new DB but same thing is happening. Using Step 7 V12 SP1 update 2. Frederik
Frederik Posts: 23 Rating: (1)
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11/18/2013 4:55 PM	Rate (0)
Frederik Posts: 23 Rating: (1)	Also I should add that in my case the TON box is NOT green, it is dotted line, even though the enable input is ON and the network is being processed each scan (it is in the beginning of OB1). I think this merely indicates that the timer is not setting its ENO, which makes sense if the timer is not timing. I also tried creating a new TON call and creating a new TON data block using defaut DB number (new never used DB number) and still have the same problem. I have a feeling this is me doing something wrong and I will end up looking stupid :) To be honest I would prefer it to be the case (me doing a stupid error) and not a funny TIA behavior.
Frederik Posts: 23 Rating: (1)	Last edited by: Frederik at: 11/18/2013 5:06 PM
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11/18/2013 6:47 PM	Rate (1)
Frederik Posts: 23 Rating: (1)	Ok I found my problem. I would say it is a mix of my fault and a (not so) funny behavior of TIA or PLCSIM... The problem was my timer testing program was oversimplified actually. Apparently, if you do not have something using the .Q bit directly (either a coil or subsequent logic in the branch, or a contact using the .Q bit) the timer will appear to not run (no ET countdown, no .Q activation in the online view nor in a watch table). I say "appear" to not run, because if I set it at 60 seconds, it will never trigger and would not countdown. But if I wait for 30 seconds with IN active (no countdown) and download the code with use of the .Q bit, I can see the timer starting from 30 seconds, proving it was actually timing. In fact if I wait for the whole PT time, and download the code with use of .Q, the output will be ON immediately, even if it was not turning on with the code that did not have the .Q use. I think this is because the timer did memorize the initial system time when the timer started, but is not counting down, and as soon as it sees that we use the .Q output it starts processing and comparing current time vs memorized initial. I am wondering if you are using an IEC timer as part of a FC or FB with no local use of the bit (for instance if you use a move block or other data transfer operation to indirectly use this timer), is the timer not going to work because it thinks you are not using it ? Or is this a PLCSIM bug only ? (I do not have the actual CPU to try it). Note: this is not only an online LAD display update issue, the values are really not updating in a watch table either. What made me try to add a use of the .Q bit is this in the help for the TON timer: The instruction data is updated both when the instruction is called and also each time the outputs Q or ET are accessed. But even then it says it should update when the instruction is called too, not only when Q or ET is accessed... Fred
Frederik Posts: 23 Rating: (1)
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11/19/2013 4:04 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/24/2025 Posts: 15558 Rating: (2468)	Fred, I too have seen odd behavior or difficult to troubleshoot behavior anyway in IEC_Timers. I have several projects with properly configured IEC_Timers that show dotted blue (not solid green) lines that operate just fine provided I access the Q in a NC/NO contact rather than relying on the Q output of the timer to activate. I routinely use TON and add a branch/rung below the TON with a NO myTimer.Q tag rather than add anything after the Q output of theTON. It is strange that in some instances the Q outputs operate as expected and other instances, they have the behavior you describe and do not seem to activate the Q output even for asingle scan. Sometimes I add a NO myTimer.Q at the Q output of the TON andtimers seem to work better or moreconsistently for me. Consistent behavior being rather important, I should think thereason the TON is in dashed blue rather than solid green should be put into the diag buffer or display when you hover over the timer block while online with thePLC.
	science guy
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11/19/2013 5:06 PM	Rate (0)
Frederik Posts: 23 Rating: (1)	I think the dashed blue line only means the block is not activating its ENO, so it makes sense that a timer not timing will not be green until it has reached its PT. Im my case, using either a separate Q contact under the timer, or adding something at the Q on the right of the timer call does the same thing, and "fixes" the timer. I am worried of cases where the compiler might not be able to see that we are actually using the Q output (for instance if working indirectly, passing timer structures to FCs or FBs, or using block moves. Did you have the strange behavior with actual PLCs or onyl with PLCSIM ? I have not done the test yet on actual PLC.
Frederik Posts: 23 Rating: (1)
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This contribution was helpful to 2 thankful Users U_9814cc1a-eb46-4... jalbarracin

6/14/2016 9:38 AM	Rate (0)
jalbarracin Regular Member Joined: 6/10/2014 Last visit: 10/3/2023 Posts: 10 Rating: (0)	Thank you for your post, it helped me a lot. You obtain the same behaviour with a real (physical) CPU. MfG

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