I am looking to upgrade some remote monitoring sites. The front end is a custom VB HMI. I am looking for some sort of modbus driver or app to integrate into the HMI that can request data from the remote sites via the land-line modems and receive the data back. The master modem is a SixNet VT Modem 1 and the slaves are COM220 Modems. The data loggers are Campbell Scientific CR800.

Any ideas or advice?

 

I have used this drivers from these folks and they worked well for me. http://www.sapia-inc.com/SMRXActiveX.htm

Bill Sturm
Abbeytronics LLC

 

Thank you for the link