With the Pioneer 6000A, the sendVideo command takes one parameter, which is the command string to send to the player. See the Pioneer 6000A manual for details on the content of that string.
However, this player does not accept normal ASCII "0"-"9" for numeric values. The sendVideo command will perform the translation from a normal numeric string to that acceptable to the player. Simply enclose the numeric string in periods; for example: ".54000.".