If you look at the extended codes for the RX-V1300 you get the first two entries:

Main Power Zone On
Custom Code 7E [hex =Decimal 126=Device]
Data Code 7E [hex =Decimal 126=Function or Command]


Main Power Zone Off
Custom Code 7E [hex =Decimal 126=Device]
Data Code 7F [hex =Decimal 127=Function or Command]

I have added the information inside the brackets. To convert hex to decimal the easiest way is to get the venerable calculator that comes with every version of Windows, under view select scientific, push the radio button for hex enter the value and then select the radio button for decimal.

Then download MakeHex from the utilities section under Pronto files. Read the readme. The protocol for Yamaha is NEC. Open up the NEC.irp file in Notepad and edit the Device= and Function= statements so it looks like this:

Device=126
Function=126..127

Protocol=NEC
Frequency=38000
Time Base=564
One=1,-3
Zero=1,-1
Prefix=16,-8
Suffix=1,-78
R-Prefix=16,-4
R-Suffix=1,-174
Default S=~D
Form=*,D:8,S:8,F:8,~F:8,_;*,_

Save this file and drag and drop it on makehex.exe and you get a file called nec.hex that has this:

Device Code: 126 Function: 126
0000 006D 0022 0002 0157 00AC 0015 0015 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0015 0015 0040 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0040 0015 0015 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0015 0015 0040 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0040 0015 0689 0157 0056 0015 0E94
Device Code: 126 Function: 127
0000 006D 0022 0002 0157 00AC 0015 0015 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0015 0015 0040 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0040 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0015 0040 0015 0689 0157 0056 0015 0E94

Here are two perfectly generated Pronto hex files for the discrete power commands.

-Jon