Accell UltraAV 2x4 HDMI AudioVideo Matrix and Distribution Amplifier K072C011B Remote Codes User Manual

							 
 
 
The 2x4 HDMI matrix remote codes are for use with the following Accell product, 
 
2x4 HDMI Matrix, P/N K072C-011B 
 
Customer code: 00FF 
Remote control NEC Format 
 
 
 
Features: 
 8 bit address and 8 bit command length 
 Address and command are transmitted twice for reliability 
 Pulse distance modulation 
 Carrier frequency of 38kHz 
 Bit time of 1.125ms or 2.25ms 
Modulation: 
 
 
Page 1  
						

							 
 
The NEC protocol uses pulse distance encoding of the bits. Each pulse is a 560µs long 38kHz carrier burst 
(about 21 cycles). A logical 1 takes 2.25ms to transmit, while a logical 0is only half of that, being 
1.125ms. The recommended carrier duty-cycle is 1/4or 1/3.   
Protocol: 
 
The picture above shows a typical pulse train of the NEC protocol with this protocol the LSB is transmitted 
first. In this case Address$59 and Command $16 is transmitted. A message is started by a 9ms AGC burst, 
which was used to set the gain of the earlier IR receivers. This AGC burst is then followed by a 4.5ms 
space, which is then followed by the Address and Command. Address and Command are transmitted twice. 
The second time all bits are inverted and can be used for verification of the received message. The total 
transmission time is constant because every bit is repeated with its inverted length. If youre not interested 
in this reliability you can ignore the inverted values, or you can expand the Address and Command to 16 
bits each. 
Output1:    number 1 keys: 00FF58A7 
Output1:    number 2 keys: 00FF1BE4 
Output1:    number OUT1 keys: 00FF16E9 
 
Output2:    number 1 keys: 00FF55AA 
Output2:    number 2 keys: 00FF17E8 
Output2:    number OUT2 keys: 00FF15EA 
 
Output3:    number 1 keys: 00FF59A6 
Output3:    number 2 keys: 00FF1AE5 
Output3:    number OUT3 keys: 00FF18E7 
 
Output4:    number 1 keys: 00FF5DA2 
Output4:    number 2 keys: 00FF1DE2 
Output4:    number OUT4 keys: 00FF1CE3 
 
     
 
 
 
Page 2