Hang Posted March 10, 2014 Report Share Posted March 10, 2014 Hi there, I have a project that need to use V1210 modbus to control a VFD which is Hitachi WJ200. Im new to PLC and never done anything about modbus. But I watched the webinars and got the frame of the software. Now, I still don't know how to connect the PLC with the VFD. I can program the PLC and make it the master, but I don't have a chance to program the VFD. I saw on the other forums that people are using March 3. I don't know what is that and I don't think that will help. So Im here to see if anyone can tell me from the basic steps how to set up the connect between the PLC and VFD through modbus. Appreciate for the help. Regards Quote Link to comment Share on other sites More sharing options...
MVP 2023 Joe Tauser Posted March 11, 2014 MVP 2023 Report Share Posted March 11, 2014 You will first need the documentation on the Hitachi describing it's Modbus address map so you know where to look for what. Then look at the Modbus master examples under the Help menu. I found the Hitachi manual describing Modbus here- http://www.clrwtr.com/PDF/Hitachi/Hitachi-WJ200-User-Manual.pdf Modbus is documented in Appendix B. The actual addresses you need are on B-24; everything before that is fairly confusing about formatting Modbus commands, which Unitronics does for you. The Hitachi uses RS485, so I'd set up the PLC on COM2 for this type of communication. Before you start writing your real program, I'd write an app that just lets you get familiar with talking to the drive. Hard code some reads and writes to specific registers and put the data and trigger buttons on the screen. Hopefully you have a helpful distributor to guide you along the way- this is a rather difficult project for a beginner. Joe T. 1 Quote Link to comment Share on other sites More sharing options...
Hang Posted March 11, 2014 Author Report Share Posted March 11, 2014 Thank you Joe. I connected the PLC with the VFD today and did some test for the modbus control. I downloaded the modbus master file like the webinar shown and change all the settings into my requirements, but it won't work. The status message is 5, which means no connection. I dont know why. I think all my wirings and setting are right. I dont know how to upload pics, hope someone can help me. Thank you. Quote Link to comment Share on other sites More sharing options...
MVP 2023 Joe Tauser Posted March 12, 2014 MVP 2023 Report Share Posted March 12, 2014 First contact is always the hardest part. 1. Can you give a detailed description or drawing of how you wired the COM port of the PLC to the drive? 2. Can you upload the test program you are using? Joe T. Quote Link to comment Share on other sites More sharing options...
Hang Posted March 13, 2014 Author Report Share Posted March 13, 2014 Hi Joe, Sorry to reply you late. Thank you for your help. I figured it out yesterday and work late, so I didnot get a chance to reply you. The problem was the master IP setting. I though the master's IP will be only for master; slave IP for slave. So I set both the master, which is the PLC and the VFD at IP 1. Also, the manual of the VFD gave me the wrong command address. I figured that out with trying some address around the address from the manual. Thank you again for your help. You replied real fast. Regards, Hang Quote Link to comment Share on other sites More sharing options...
Hang Posted March 13, 2014 Author Report Share Posted March 13, 2014 Thanks Joe, I have figured that out. It was because the IP setting and the wrong address from the VFD manual Hang Quote Link to comment Share on other sites More sharing options...
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