31）data6bit-a

data6bit-a是一种常见的编码格式。

该格式来源于祝成万能遥控器ZC-18A码组号673. Features 基本特点：1、6位数据码；

2、脉宽调制方式（PWM）；3、载波：33.3KHZ；

4、逻辑位的时间长度是2.396ms或4.776ms。Modulation 调制1、逻辑“0”（Logical“0”）是由576us的33.3KHZ载波和1820us的无载波间隔组成；（图中表示的是有载波和无载波间隔的总长度）2、逻辑“1”（Logical“1”）是由576us的33.3KHZ载波和4200us的无载波间隔组成。

Protocol 协议

从上图可以看到data6bit-a一帧码序列是6位数据码。

长按键不放，发出的码波形序列如下图。就是将第一帧波形以周期

58.092ms进行重复。

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32）data6bit-c

Features 基本特点：1、6位数据码；

2、脉宽调制方式（PWM）；3、载波：20KHZ；

4、逻辑位的时间长度是2 ms或4ms。Modulation 调制1、逻辑“0”（Logical“0”）是由1000us的20KHZ载波和1000us的无载波间隔组成；（图中表示的是有载波和无载波间隔的总长度）2、逻辑“1”（Logical“1”）是由1000us的20KHZ载波和3000us的无载波间隔组成。

Protocol 协议

从上图可以看到data6bit-c一帧码序列是6位数据码构成。

长按键不放，发出的码波形序列如下图。就是将第一帧波形以周期

72.5ms进行重复。

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33）X-Sat Protocol X-Sat Protocol

I call this the X-Sat protocol because it is used in the X-Sat CDTV 310 Satellite receiver made by the French company Xcom. This protocol is probably also used in other X-Sat receivers, but I have no means to verify that. I haven't seen this protocol anywhere else but that doesn't guarantee that it is unique to the X-Sat brand. Features

8 bit address and 8 bit command length Pulse distance modulation Carrier frequency of 38kHz Bit time of 1ms or 2ms Modulation

The X-Sat protocol uses pulse distance encoding of the bits. Each pulse is a 526祍long 38kHz carrier burst (about 20 cycles). A logical \1.0ms. The recommended carrier duty cycle is 1/4 or 1/3.

Protocol

The picture above shows a typical pulse train of the X-Sat protocol. With this protocol the LSB is transmitted first. In this case Address $59 and Command $35 is transmitted. A message is started by a 8ms AGC burst, which was used to set the gain of the earlier IR receivers. This AGC burst is then followed by a 4ms space, which is then followed by the Address and Command. A peculiar property of the X-Sat protocol is the 4ms gap between the address and the command. The total transmission time is variable because the bit times are variable.

An IR command is repeated 60ms for as long as the key on the remote is held down.

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34）Philips RECS-80 Protocol 38kHz carrier

This protocol is designed by Philips and transmitters are produced by Philips (SAA3008) and ST (M3004). Personally I have never seen this protocol being used in real applications. All information on this page is derived from the data sheet of the Philips SAA3008 and the ST M3004 (10624.pdf).

There are 2 small differences between the two competitor ICs. The Philips IC has two modes of operation, one which is compatible with the ST chip and one which can handle up to 20 sub-system addresses. The ST chip has the capability of switching the modulation carrier off. Features

7 or 20 sub-system addresses, 64 commands per sub-system address 1 or 2 toggle bits to avoid key bounce Pulse distance modulation

Carrier frequency of 38kHz, or unmodulated

Bit time logic \

Command repetition rate 121.5ms (55296 periods of the main oscillator) Manufacturer Philips & ST Modulation 1/3 duty cycle

Normal Protocol

The drawing below shows a typical pulse train of a normal RECS-80 message. This example transmits command 36 to address 4.

Usually the first pulse is a reference pulse, with a value of \the exact bit length.

The next bit is a toggle bit. Its value is toggled whenever a key is released, which results in a different code every time a new key is pressed. This allows the receiver to discriminate between new key presses and key repetitions.

Only the ST chip M3004 can disable its carrier, in which case the REF pulse is interpreted as a second

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