How to use the Tally function of Syscom 421? Hollyland Tech September 07, 2021 10:01 Updated Overviews: Tally function is significant for on-site shooting and making shooting easier and more efficient, the connection between Syscom 421 and Switcher will be shown in the below article. Please check the picture below to get how to connect our device to the switcher (SONY/Panasonic/Datavideo). You Need: Tally Converter (From Hollyland) Customize Tally Cable Tally Indicator Please check the picture below to get how to connect the BMD switcher: Related articles More How to connect Syscom 421 with PTZ camera? User Manual TUTORIAL Brochure Comments 0 comments Article is closed for comments.