The video signal must be 1080i with 10 bit color depth according to ITU-R BT.1120. Like for DVB Teletext you can select the 32 "virtual" VBI lines to be transmitted and can this way control the Teletext data rate. The VANC lines of the HD-SDI signal to be used for the transmission are also selectable. If you use SMPTE 2031 Teletext you only need one HD line. For OP-47 you may need up to 5 HD lines depending on the data rate.
For more information about the HMS teletext solutions please visit our TTX product page.