Quick Start Guide
Global Caché
GC-IRE
IR Extender
Overview.
The GC-IRE IR Extender is a new concept in automated controls that
allows IR devices, such as remote controllers, to act as digital input devices in a
networked environment. The GC-IRE digitizes IR inputs from a Global Caché,
Xantech, or SpeakerCraft IR receiver or distribution block. By converting this IR
information to serial ASCII text, IR can now be considered a new input method for
digitally controlled installations.
The GC-IRE has two interfaces, a 3.5mm stereo jack for IR input and a serial
RS232 male DB9 connector for ASCII text output. The serial connection provides
both power (no external power supply is required) and two-way communication for
GC-IRE configuration and IR output. Additionally, an IR noise measurement mode
is available to assist in proper placement of IR receivers to minimize background
IR interference. The GC-IRE samples IR input including background noise and
modulation frequency. It then attempts to filter out incomplete IR commands,
background noise, and incorrect IR patterns before transmitting good IR commands
as serial ASCII text.
Getting Started.
A simple method to become familiar with the GC-IRE is to
connect it to the PC's RS232 serial port and send commands using Windows Hyper
Terminal. Hyper Terminal can be found under
Programs/Accessories/Communications in the PC's Start menu. After selecting
Hyper Terminal, enter a name such as, PC_9600 and click OK. When prompted
with “Connect using,” select COM1, not TCP/IP. In the next window; for “bits per
second” select 9600; for “data bits” select 8; for “parity” select none; for “stop bits”
select 1; and for “flow control” select none. Now click OK to complete your Hyper
Terminal setup.
Plug the GC-IRE into the PC's COM1 serial port. Since power is supplied by the
RTS line (pin 7), flow control (handshaking) must be disabled for proper operation.
At power up, the ACT indicator will blink once and then remain on. This indicator
will also blink when receiving IR signals, to indicate IR activity. Type gv
↵
in the
Hyper Terminal window to obtain the version number of the GC-IRE.
The GC-IRE is ready to receive IR information. Plug in a Global Caché IR receiver
(GC-RF1 or GC-RG1) or a GC-CXG from a Xantech and SpeakerCraft IR
installation to the "IR IN" 3.5mm stereo jack. As IR is received the ACT indicator
will blink and the IR digitized output will be sent to the open Hyper Terminal
window.
IR Encoding and Transmission.
The GC-IRE transmits IR signals in real time as
comma delimited ASCII text terminated by a carriage return (
↵
). Other terminators
may be used, see command set. An IR signal is a sequence of ON and OFF states
modulated with a carrier frequency ( ƒ ) during the ON state. Most IR remote
control devices operate at frequencies near 40KHz with some devices operating up
to 500KHz. The ON and OFF timing is measured in periods (
τ
) of the carrier
frequency, where
τ
= 1/ƒ. For example, an ON state of 24 represents 600µS for a
carrier frequency of 40KHz, (600µS = 24 / 40,000Hz).
