Feedback from Korolev Alexey, support engineer, Yacht Devices Ltd I am interested in controlling a power switch (like the Switch Control YDSC-04) YDSC-04 is a button panel. Do you mean YDCC-04 unit (relay block)? > from an NMEA 2000 Tool running on a PC. You need a NMEA 2000-to-PC gateway which can send arbitrary PGNs to NMEA 2000 network, like our: - NMEA 2000 USB Gateway YDNU-02 https://www.yachtd.com/products/usb_gateway.html - NMEA 2000 Wi-Fi Gateway YDWG-02 https://www.yachtd.com/product s/wifi_gateway.html - NMEA 2000 Ethernet Gateway YDEN-02 https://www.yachtd.com/product s/ethernet_gateway.html You can use our CAN Log Viewer software to control YDCC-04 https://www.yachtd.com/product s/can_view.html >I see from the documentation that PGNs 127501 and 127502 are supported, Correct, our device supports standard NMEA 2000 digital switching PGNs. > cannot find out exactly how PGN 127502 is used. Send PGN 127502 \"Switch Bank Control\" to NMEA 2000 network to change the YDCC-04 relay states. Read PGN 127501 \"Binary Status Report\" off the NMEA 2000 network to get the actual YDCC-04 relay states. >For instance is PGN 126208 used to command the field referencing the switch of interest? YDSC-04 (button panel) can, indeed, send this PGN, it is used for Maretron and Carling Tech equipment compatibility. We do not recommend to use this PGN to control the YDCC-04 from a software, better use PGN 127502 \"Switch Bank Control\". >Is there any sample scenarios or code explaining the usage of the switch at the PGN level? Check the attached program for our NMEA 2000 Bridge YDNB-07 [ implements YDCC-04 auto-OFF feature, shows how to read and set states via PGNs 127501 and 127502 ] https://www.yachtd.com/product s/nmea_bridge.html Feel free to ask more questions if you need more help. Best regards, Korolev Alexey, support engineer, Yacht Devices Ltd www.yachtd.com