To quickly test a plc output which is wired to a relay do I dob a cable between the output and 24vdc+ source I.e something with 24vdc+ live such as a terminal. I know it’s all wired correctly but I’m not a plc engineer and just want to test and prove by bringing in the out put the relay changes state. So is it one end of cable to 24vdc+ terminal and other dobbed on output? I thought I’ve heard people say it’s on a 0v leg but just want to know !