The ATOMOS Connect Converter H2S: HDMI to SDI is a convenient way to convert an HDMI signal to SD, HD, or 3G-SDI -- depending on the transfer rate of your SDI device -- for the purpose of running the HDMI signal on an SDI device (such as in, for example, connecting a camera monitor to the Converter by HDMI, and outputting the signal to a big screen SDI monitor 300 feet away).
 
https://www.bhphotovideo.com/c/product/829877-REG/ATOMOS_ATOMH2S001_Connect_Converter_H2S.html