9/7/2017 3:12 PM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating: (1365)
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Dear user,
Normally standard timers doesn't support pause or holding capability.There is an FB developed many years ago and it is available in the forum as a multi-function timer with a pulse signal.You can call it in one of the OB3X and sample rate of the cyclic interrupt is added to a register and compared to a set value.It is developed in STL and you can find it in the following link: Timer which does not reset itself
As calculations are performed on real, there is a limitation in SIMATIC S7 to add a small number with a huge number.To avoid this, consider another registers to keep hours passing.When you work with huge time spans such as 16 hours , a slight calculation around 1s can be tolerated. There is another sample for SFB4 with similar functionality, you can find it in the forum. I hope it helps, hdhosseini |
This contribution was helpful to2 thankful Users |
9/7/2017 4:25 PM | |
Joined: 9/27/2006 Last visit: 9/20/2024 Posts: 12282 Rating: (2684)
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Hello Mohanna; First thing: the Clock memory its are based on the hardware clock of the CPUs (except the S7-312, which has a software clock). Accuracy values for the RTC on the S7-300 and S7-400 are shown as attachment below. You will find info on the Clock memory in the following discussions: Cyclic Interrupt or Clock Memory - http://www.plctalk.net/qanda/showthread.php?t=35209 There is a retentive TON (TONR) available for S7-300/400 CPUs: S7 FC80 TONR (TI-S7 Converting library in Simatic Manager); TONR_X is the TIA Portal equivalent instruction. STEP 7 - System and Standard Functions for TI-S7 What I have not found out is the maximum PV value you can use with these timers. I presume that the Online Help can provide this. Hope this helps, Daniel Chartier |
Last edited by: dchartier at: 9/7/2017 4:36:48 PM |
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This contribution was helpful to1 thankful Users |
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