Hi John,

You know, I should be able to do this by now, but I still have a mental block when given the following info.

Here is the info provided by the manufacturer:

The remote control and the VS-4 communicate using the NEC IR protocol which uses a carrier frequency of 38 kHz. The format of the IR packet transmitted by the remote
control is as follows:

8 bits – MSB of the device address
8 bits – LSB of the device address
8 bits – Function (command) code
8 bits – complement of the Function code

An example would be useful at this point, so we will use the Power Toggle key. The
Power Toggle key on the remote control toggles the power on and off. Here are the bytes for the packet:

MSB of the device address = 0xA2
LSB of the device address = 0xF9
Function code (Power Toggle) = 0x9A
Complement of the Function code = 0x65

Here are the function codes and their behavior for each state of the VS-4:

These are the codes I need:

Discrete Power Off 0x98 (152)
Discrete Power On 0x99 (153)
Power Toggle 0x9A (154
Input 1 0x90 (144)
Input 20x91 (145)
Input 3 0x92 (146)
Input 4 0x93 (147)

Any help with be appreciated.

Thx Dave

It's hard as usual to guess whether the manufacturer is documenting the bits within each byte in the standard NEC manner or backwards.

If standard, then the condensed Pronto Hex for power toggle is
900A 006D 0000 0001 A2F9 9A65
which with NEC1.irp is device=162.249 Function 154

If backwards, then
900A 006D 0000 0001 459F 59A6
which with NEC1.irp is device=69.159 Function 89

Thank a million, John. I will try these.

Is the MSB (most significant bit) or LSB (least significant bit) any clue to what the manufacturere had in mind, regarding order? I have heard the LSB is usually first, which of course doesn't help us determine the true order.

Thx Dave

Yes, MSB vs. LSB is exactly the question I was unsure of.

NEC protocol sends LSB first. If the manufacturer documentation is consistent with that fact then they will document in hex or decimal with values that, when converted to binary, must be read right to left within each byte in order to match the actual transmit sequence.

Still makes my head spin at times, John. Thanks again for the help. I used the NEC.irp within MakeHex, set for 162.249 and the codes did work!

Many thanks!

Dave