Switching From RSLogix to Siemens TIA V13

[Tlogix]

I was wondering if I'm making a good move switching to siemens its a different animal as far as the programing goes it looks like a steep learning curve. But it looks like as far as the modbus communication goes its a lot more flexible if you have to communicate with a lot of different VFDs. Just wondering if theres some one out there that has switched and how easy or hard did you find it to pickup on the programing?

[JRoss]

AB and Siemens are very different, so there is definitely a steep learning curve. Whether it's worth it depends on a lot of different factors. Tell us a little more why you think you should/shouldn't be switching.

[Tlogix]

I work with a lot of different VFDs thru ModBus and the MSGs in AB can end up being a long ladder project. For example if I setup a system for 20 VFDs of the same brand and customer 1 wants to read/write to 10 registers Thats fine but lets say I sell this to customer 2 with the same VFDs but he wants to look at the same 10 but also wants to look at one other one thats 3 registers lower Like I'm reading 40001 length 10 customer 2 wants to also read 40016 thats when it gets ugly and if you want to keep everything organized you have a lot of addressing changes to make and adding one more MSG between the 2 reads and 3 write you have per VFD. What the Siemens sales person showed me how I could use a MSG or ModBus command in a S7 looks to be what I always thought ModBus should be setup like. For example lets say the customer wants to look at 40001 length 3 then 40015 40018 the way I understand I can make a Block or whatever Siemens calls it to read different addresses in the same ModBus block where in a AB I would have to use 3 different MSGs because of the way the VFD programer decided to structure His Registers If I try and use a MSG to read/write 40001 length 18 if 16 is not in the VFD it gives me a illegal address fault. Thats just one of the problems I run in to and in itself looks like a good reason to Switch I know It won't happen over night but I am willing to learn if I have to. Unless theres something I missed in the AB PLC witch I am sure I didn't.

[JRoss]

Yes, Modbus with the AB series is not an easy thing. You can get third-party gateway modules that make things significantly easier, though they are additional cost. And with AB generally costing more than everybody else already... Cost is generally the number one reason I've seen people moving away from AB. On the other hand, since you already have a customer base with AB machinery, and more importantly a working code base, is the engineering time to learn Siemens and convert your code worth the simplicity of the Modbus block? That's really only something you can answer. Another point. I helped an OEM customer move from AB to Mitsubishi years ago, only to see them move back recently. The reason was they had many customers who required them to use AB products, and they ended up supporting both platforms for their product line. The savings wasn't worth the hassle. I'm not trying to talk you into sticking with AB, just trying to help you make a good decision. Siemens makes a solid product.

[mohssen]

Hi there, Ibelieve JRoss is right about switching from AB to Siemens. Actually, It won't worth to change all the Hardware and software of your control system just because of some difficulties you are facing with Modbus and EIP communication. I am well familiar with Siemens control systems and I can say Siemens has better performance in many aspects than AB, However, if you have an stablished control system, just keep going with it and find solution for it. Thinking of changing everything should have been made before designing the control system! By the way, there is a very small cheap and tiny module which can convert EIP to Modbus (TCP or RTU). It is very efficient for connecting your AB to a Modbus network. Please check GW-7472 module in bellow http://www.icpdas-usa.com/i_7188e3_232.html?r=mohsen feel free to put your point of view here for us to talk more about AB and Siemens Good Luck

[DanW]

>By the way, there is a very small cheap and tiny module which can convert EIP to Modbus (TCP or RTU). It is very efficient for connecting your AB to a Modbus network. Please check GW-7472 module in bellow The link directly to the EthernetIP/Modbus gateway/bridge is http://www.icpdas-usa.com/gw_7472.html