PLC Next Clock Pulse Error

secayasar · October 27, 2020, 7:55am

Hi Everybody, We have made a simple program in PLC. Our Plc is AXC F 2152 as you see in attached file there is a simple 50ms clock pulse program. But in logic analyzer u can see that the width of the pulse is different in some times. We are using outputs with this clock pulse for a test stand. Also we can see the output leds are not blinking regularly. Our Cycle Time is 1ms. Also if we decrease the pulse time plc is not working regularly. Could you pls help.

eduardplcnextteam · October 27, 2020, 9:26am

Hello secayasar, could you send me the Task Sessings, please? Do you set the Task WD also to 1ms? ~Eduard

secayasar · October 27, 2020, 10:31am

Hello Eduard, Thx for your fast reply. I also set time WD time to 1ms. Nothing changed. I attached the task settings. Best Regards.

eduardplcnextteam · October 27, 2020, 10:37am

Hello secayasar,

are you using the last FW 2020.6?
Could you send me the two programs or the project archive for reproduction?

For uploading data to the ShareFile server, please use the following server link: https://phoenixcontact.sharefile.eu/r-rf06a5b174e44ecf8 Thanks! ~Eduard

secayasar · October 27, 2020, 11:38am

Hi, I have uploaded the program. and also version is 2020.6.1 (20.6.1.30859) Attached file u can see Best regards.

eduardplcnextteam · October 27, 2020, 3:08pm

Hello secayasar, I don’t receive you program, but try to implement the LD Program as follows, I hope it will resolve this issue. If not, please let me know. Thanks & Best Regards Eduard TON FB

secayasar · October 27, 2020, 3:30pm

Hi I tried your logic but nothing changed. I uploaded again. Could you pls inform. Best Regards.

eduardplcnextteam · October 28, 2020, 11:25am

Hello secayasar, I’ll analyze this issue and give you a feedback asap. Best Regards Eduard

eduardplcnextteam · October 28, 2020, 2:22pm

Hello secayasar,

I would like to give you a first feedback of my analysis. I have implemented a program that allows to generate a Clock Pulse with a precision of +/1 ms. In the next time I’ll analyze the LogicAnalyser functionality. I would like to demonstrate and provide you the implemented program, please contact me directly via the following e-mail: emuenz@phoenixcontact.com

Thaks & Best Regards Eduard

eduardplcnextteam · October 30, 2020, 8:04am

Hello secayasar, I analyzed the precision ob TON FB (logic shown above) in a test scenario based on the Mikrotik RTC. The accuracy of the 25 ms clock pulse is also 25 ms - 26 ms (25 ms / + 1 ms). The Logic Analyzer has a lower priority and can be interrupted by a real-time program. This is the reason, why the signal is not being logged as expected. If you need more test details, please contact me directly. Thanks & Best Regards Eduard