Do the AVN series encoders support Closed Captioning ( CC )? EIA-608 & EIA-708 supported

Yes and No. The AVN2XX encoders (AVN200, AVN210, and AVN220) support CC EIA-608 only (more info below). The AVN420 and AVN422 do not support CC. The AVN441 supports EIA-608 on the SD Composite input only (Component Y/G / luminance input), The AVN443 supports EIA-608 & EIA-708 on the SDI input only. For a complete comparison of AVN series encoders click here.
More information on CC in the AVN2XX encoders:

VSI supports both EIA-608 only in the AVN2XX Encoder line. The incoming analog signal may contain encoded CC(closed captioning) data on line 21 NTSC EIA-608 (during the VBI) which the AVN2XX will pull out and stuff into the encoded MPEG data stream for transmission according to ATSC EIA-708. A CC compliant decoder such as an Aminet will then extract the EIA-708 and place it back in the VBI line 21(EIA-608),along with the normal video picture for the display device