External Control
6.2
Using Discrete IR Codes
The DHD Controller accepts commands in the form of IR signals that conform to the Phillips RC5 protocol. Each DHD Controller remote control button has an RC5 control code associated with it.
You can use these codes to program a
IR Command Protocol ➤ The IR control codes have the following characteristics:
•Each code consists of 14 bits:
•Two (2) start bits (always 1);
•A toggle bit. This bit is inverted every time a key is released and pressed again. This enables the DHD Controller to distinguish between a button that remains down and one that is pressed repeatedly.
•Five (5) address bits. The default address is 17 (binary 10001). To change it, select Remote Control from the Service menu and follow the steps given on page 67.
•Six (6) data bits.
•The carrier frequency is 36 kHz, with the modulated pulses having a 25% duty cycle.
•Commands are sent at a maximum rate of 9 Hz.
For example, here is the RC5 control code for the ON button on the DHD Controller remote control unit (assuming the default address is used):
With Toggle Bit = 0
Hex |
| 3 |
| 4 |
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| 1 |
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Binary | 1 |
| 1 | 0 | 1 |
| 0 |
| 0 |
| 0 |
| 1 |
| 0 | 0 | 0 | 0 |
| 0 | 1 |
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Hex |
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| C |
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Binary | 1 |
| 1 | 1 | 1 |
| 0 |
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| 0 |
| 1 |
| 0 | 0 | 0 | 0 |
| 0 | 1 |
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Function | Start | Toggle |
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78 |