Sets which ports will be used for subsequent IR transmissions. The bits of P represent the 8 IR ports, IR0 being the LSB, IR7 the MSB. A "1" bit will indicate the the port will be used. Since this command is generally used before each IR transmission to specify which ports it will go to , the Slink-e will not send response to verify this command. You can still issue a get IR transmit ports if it is necessary.