text: <s>[INST] Motion Instruction MCD ( Motion Change Dynamics ) Do we have to hold rung true in front of this instruction to get it to work correctly? Or do we just one shot it? [/INST] Bruce, take a look to the attached picture... As you see, it executes in one scan normally; anyway it is better to chech the status of .DN bit to make sure everything has gone well.However it is a transitional instruction, so it executes fine with one shot, when rung condition changes from false to true. From RS5000 Ref. Manual Some relay ladder instructions only execute when rung-condition-in toggles from false to true. These are transitional relay ladder instructions. Motion Instruction Reference Manual pagg. 111-117 - fuzzy logic \\n </s>