DPP-M55 (serv.man2) - Sony Other Service Manuals Service Manual (repair manual). Page 13

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• Transmission speed

The transmission speeds vary 9.6/19.2/38.4/57.6/115.2 kbps, or 1.152/4 Mbps.
Communication starts from the station detected at 9.6 kbps. When the other party is detected, information is exchanged

at the maximum data speed which can be used by both parties, and communication is performed at that maximum speed.

In the case of cable communication using RS-232C, communication is full-duplex transmission in which transmission

and reception are simultaneously performed. IrDA is on the other hand half-duplex transmission in which transmission and
reception are switched.

• Light intensity

To realize 1 m communication, light intensity of over 40 mW/sr is required. To prevent disturbance of communication

by other infrared devices, the upper limit of the light intensity is set to 500 mW/sr.

• Communication errors

The IrDA method is equipped with a error-correction function, but errors result when communication problems occur

over a long period of time.

As infrared ray is cut off by obstacles, make sure that the optical axis of the infrared ray is not blocked. Fingerprints on

the filter in front of the transmitter and receiver will also cause a drop in the received light amount, resulting in errors.

Infrared ray is found in direct sunlight, light of lamps, and LCD panels. These cause communication noise, as do infrared

ray remote control signals of TVs, etc.