Siemens S7-200 alike

[ecvetek]

Hello, I have an aplication using a Siemens S7-200 PLC, with a very low end and easy logic. I would like to expand my application to multiple machines on which i basically just count +1 from sensors. Since S7-200 is not that cheap (for my purpose) im looking for an alternative on which i can apply the same logic as i have on existing S7-200 PLC. All I require a mudbus connection and at least 6 digital IO for my sensors. No need for outputs or anything else. Can you help me pick a good alternative within resonable price range? :) Thanks and best regards :)

[Crossbow]

There are programmable relays like Siemens Logo, Omron Zen, AB Pico, but I am not sure how many of them can talk Modbus. They are like lite versions of PLC, with limited functionality, but are much lower cost. Nothing will program exactly the same, you will have to rewrite your code. Also keep in mind S7-200 is old (obsolete, not sure discontinued), you should be using S7-1200 now.

[ecvetek]

The modbus option was, well i hoped for, an upgrade. As i'm checking the software now, it seems the modbus connection was never coded till completion so i guess i'll have to stay with serial connection, In that case...now i was using S7-200 with PPI/PC cable connected to RS232 on my server. And as you said S7-200 is obsolete. What do you purpose i buy instead? i would need like 10 of sets like that. So if it exist a PLC with RS232 would be great. But then a new problem. Due the long range i will probably need a RS232 to ethernet adapter and a virtual ports on server (thats why i was hoping for modbus). I suppose that will do the trick, any suggestion on adapter? :) Many thanks in advance :)

[Crossbow]

Why mess around with serial to Ethernet and converters? Why not just look at a PLC with Ethernet? As I said, S7-200 was replaced by S7-1200. So if you want to remain with Siemens, that is your upgrade path. If you look for other vendors, there are plenty who have serial or Ethernet options in a micro sized controller.

[a062549]

I used several of the IDEC controllers and they are reasonable. They are Modbus native and etherneted.

[Bryll]

Delta is a quite cheap system to buy, the software is free for download from their website. Delta ISPSoft download page

[kollewin]

Hello I don't know if u used compatible S7-200 PLC,the funcation is same with Siemens . And it can reduce your cost ,improve your equipment effienciency. Like SM7-200 DIGITAL MODULE ,SM7-200 ANALOG MODULE . Please check attachment for details. E-mail:shelia@kollewin.com shelia@kollewin-Tech.com