The Hall Technologies HR-4P is a programmable RS-232 device designed for control & automation of a Projector, LCD, or any other device with serial or IR port.
The unit has 4 configurable I/O lines that can be defined individually to act as input or output. When configured as input, they sense contact closures or Voltage levels (user defined as pull-up or pull-down). Upon detecting "Low-to-High" or "High-to-Low" transitions the unit can issue programmed Serial RS-232 Commands, as well as IR commands for controlling infrared equipped devices. When configured as output, the I/O pin can be commanded to short to ground (open collector and high voltage open circuit tolerant) perfect for controlling external relays.
The unit can also control devices that do not have RS-232 port by converting RS-232 commands (or contact closure external switch inputs) to IR commands. If the IR command standard (e.g. NEC, RC5, SONY, JVC) and strings are known, simply program them. If not, the unit has the ability to learn the IR codes (even for non-standard formats) and play them back (requires optional IR detector cable).