profibus / modbus

Iam working on link PLC S7-317 2PN/DP as master using profibus to two old slave speed drives which have only modbus (rs-485)

after search I found

https://www.adfweb.com/home/products/Profibus_to_serial.asp

choosing their module

https://www.google.com/url?hl=en-GB...460000&usg=AFQjCNEj188vmt_vlUp6xuWHA9a8Bm_NeA


Is any body used this company product before or used this module?

Any help

Hello!
You can use the following Prosoft industrial gateway Profibus Slave to Modbus Master/Slave 5105-MCM-PDPS. Connect this module as Profibus Slave to S7-300 as Profibus Master. And then connect your VFDs as Modbus Slaves to Prosoft Gateway as Modbus Master.

http://www.prosoft-technology.com/P...bus-Master-Slave-to-PROFIBUS-DP-Slave-Gateway

http://www.prosoft-technology.com/content/download/1205/9015/version/5/file/MCM_PDPS_Datasheet.pdf

I use different Prosoft modules for a long time and they work pretty well. And Prosoft tech support is great also.

Oleksandr_Husyev said:

Hello!
You can use the following Prosoft industrial gateway Profibus Slave to Modbus Master/Slave 5105-MCM-PDPS. Connect this module as Profibus Slave to S7-300 as Profibus Master. And then connect your VFDs as Modbus Slaves to Prosoft Gateway as Modbus Master.

http://www.prosoft-technology.com/P...bus-Master-Slave-to-PROFIBUS-DP-Slave-Gateway

http://www.prosoft-technology.com/content/download/1205/9015/version/5/file/MCM_PDPS_Datasheet.pdf

I use different Prosoft modules for a long time and they work pretty well. And Prosoft tech support is great also.

Click to expand...

thank you for your replay

Do you have any examples for using s7-300/400 using this gatway

No, unfortunately I have never used this gateway. But you won't meet any problem with it. You add GSD file of gateway in your Step7 project and connect it to your PLC as Profibus DP slave.
Then you need to configure the gateway with Prosoft Configuration Builder software to work as Modbus Master and connect your VFDs as Slaves. You can find more info in gateway's manual.

Regards, Oleksandr.

I've done some profiNET (not profiBUS) to modbus RTU using anybus module.

The main thing is to understand and strictly follow the modbus standard. For example, to set a single coil (1 bit) you don't write a 1...you write 0xFF00 (16 bits) but to write multiple coils you write bytes using 1 bit/coil. Also modbus RTU is even parity by default so best stick to that...if you need to run no parity, then you need to set up for two stop bits to maintain 10bits/byte....lots of little gotchas in the modbus standards. If it isn't working, dig into the modbus spec, and find what you are doing wrong...my experience is that it behaves very robustly once you get things correct.