Posted 23 Jul 2015 hello everyone I wrote a program that by positive edge of two inputs as Starts button the motor sets and by positive of stop buton rests it , but it doesn´t work . please help me and say why this problem .thanks OB1.pdf Share this post Link to post Share on other sites
Posted 23 Jul 2015 just remove pulse (edge) instructions. what is the chance that you will get two start buttons pressed at the exact same time? 1 person likes this Share this post Link to post Share on other sites
Posted 23 Jul 2015 Should be 'OR' not 'AND'. No need for one shot edge if its a normal start/stop. If your looking for a safety style start, two buttons together, then you would need bigger changes Share this post Link to post Share on other sites
Posted 23 Jul 2015 if it was OR, single button could be used as start. I don't think that is what he is after Share this post Link to post Share on other sites
Posted 26 Jul 2015 The question was not clear on that but I did cover the two buttons together at the end of my reply by stating that if that is what he is after, which normally a safety application, he would need more than what he has done. He would need to ensure that the buttons are pressed within a short time of each other. Also if it is a safety application he shouldn't be doing it in the PLC, unless it is a safety PLC, there are hard wired two button press safety relays Share this post Link to post Share on other sites