Set IR Receive Polarity

Command Code

Binary: [1 0 0 1 1 1 1 1] [0 0 0 0 1 0 1 1] [ports]

Description

(Slink-e 2.0 and above only)

This command sets the receive polarity of the IR zones. The receive polarity is whether the Slink-e considers an IR on or off pulse to be what it is or the opposite. If you set the receive polarity in an IR zone to Inverted, the Slink-e considers an IR on pulse to be an off pulse and vice versa.

Inverted polarity is worse than useless with real IR messages. Not only does it serve no purpose, it causes the Slink-e to go into an extended receive state and become unresponsive when it should be idle, because the Slink-e uses extended off pulses to mark the end of an IR message. With inverted polarity, extended off pulses are ridiculously long on pulses.

What Inverted polarity is for is applications where you use the IR port (in zones other than zero, which receive electrical signals that are supposed to represent IR signals) to receive electrical signals that do not in fact represent IR signals. A good example is S-link Control-S.

At the electrical interface to the IR port, a low voltage (0 volts) indicates presence of IR light and high voltage (5 volts) indicates absence of light (the protocol is active-low). If you turn off the IR carrier, that means low voltage means an on pulse and high voltage means off pulse. So with Inverted polarity, Slink-e acts as if it is receiving an off pulse when it sees low voltage and an on pulse when it sees high voltage.

The "ports" byte gives the polarity settings. Each bit of the byte corresponds to an IR zone in order, with the least significant bit being Zone 0. A 1 means Normal polarity. A 0 means Inverted polarity.

The factory default polarity setting is all zones Normal.

Use an Get IR Receive Polairty command to query the receive polarities.

Responses

The Slink-e normally generates a IR Receive Polarity Is Control Report to confirm that it executed your command.