Infrared control is used to provide line of sight wireless communication for distances of at least 1 meter. A low power mode can be used up to 20cm with battery powered devices. The PC99 Specification requires the use of 4Mbps parts. Older units may be slower. Communications may be uni- or bi-directional.
Data rates vary from 9600 bits/Second to 4Megabits/Second. 115200/Bits per second is a commonly used speed. A 16bit CRC is used at 115KBits/Second and a 32 bit CRC is used at 4MegaBits/Second.
A number of protocols are defined for Ir communication of pictures, objects, etc. Provisions are made to connect to serial/parallel/USB ports or to hook into standard networks via adapters. Multiple data streams can be multiplexed onto an IR link
There appears to be a separate and distinct 75Kbits/Second IrDA control interface to be used with devices such as keyboards, joysticks, mice and similar control devices. This permits ranges up to 5 meters and is supported by Win98.
Note: The IrDA descriptions I have found are extremely confusing.
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