Updated January 30, 2026
VTScada should work with any standard voice or SMS modem. Though we cannot guarantee the compatibility of third-party modems across all Windows operating systems, our team has provided the following comments on modems that we have used by us or our customers. We have no relationship with these manufacturers.

Fewer and fewer manufacturers are offering physical modems. There will likely be none in the near future. For voice or SMS alarm notifications, we suggest migrating to VoIP (see post below) or the third-party platform Twilio.

The following devices have been tested in-house.

Dialup Voice Modems

• StarTech - USB 2.0 Fax Modem 56K External Hardware Dial Up V.92 Modem/Dongle/Adapter - Computer/Laptop Fax Modem USB to Telephone Jack USB Data Modem - Network Fax/ Voice/CMR/POS

Cellular SMS Modems

• MultiConnect microcell MTCM-L1G2D-B03-KIT
• MultiConnect microcell MTCM2-L4G1D-B03-KIT

For more information, see the VTScada help file entitled, "Modem Configuration and Use."

An Alternative to Voice Modems – No Internet Required

VTScada will support physical voice modems for alarm annunciation as long as they are available. However, it is increasingly difficult to find companies that produce them. Soon there will be none.

The good news is that you can now move beyond this hardware and take advantage of the benefits of VoIP without going through the internet. Version 12.1 allows you to use an analog telephone adapter (ATA) or your existing VoIP phone system to send voice alarm notifications to operators.

For more information, see the VTScada Help file:
https://www.vtscada.com/help/Content/D_AlarmSystem/Dev_VOIP.htm?Highlight=voip