Alison Posted March 3 Report Share Posted March 3 Hi all. I am brand new to all this, so please don't savage me too badly. I have a Vision 350 here, and I want to get it talking to two different Modbus machines - a heat pump and a variable speed motor drive. Initially I just want to poll the units from my Vision to find out stuff like speed of drive, or heat pump temp. I have modbus "maps" for both units so that helps! Eventually I'd like to use the Vision to control our entire pool set-up - I work for a swimming pool equipment wholesaler. This is really just me trying to teach myself something new, but getting more control over the VSD would be great (eventually). I've started off following the videos on Modbus and on PLC basics but I'm struggling with some things, just because I'm no programmer and this is all new to me. Could anyone please suggest some good starting points - tutorials, videos, further reading - that might help? For example I don't know why, as the first step in the Modbus vids, a system bit is used in the first net. I must have missed what this is/does somewhere - I feel like I have missed a set of videos inbetween the "What is a PLC/HMI" and "How to work Modbus" ones!! Thus far my understanding is that you make a pretty interface screen, tie the things you're doing on that screen to "nets" (which are basically steps in a program) and the Vision will follow the structure of the ladder from top to bottom. I *think* that the Vision (as Master) polls the Slave units, gets data from them from whichever modbus address I point it at, loads that data into its own memory and uses the data as variables that I've defined, then keeps on repeating that process. Am I anywhere near right, here? Thanks Alison Quote Link to comment Share on other sites More sharing options...
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