i want to use reset button to reset the operation. after that , i want to push the start button to run the machine again. i found that, when i push reset button, it will disable start button.
You haven't provided enough information. You might solve your problem by modifying the PLC program or you might have to rewire something. Either way, nobody here is clairvoyant. We don't know the details of your machine or the program controlling it.