products have become the interface of choice for all high definition equipment.
Many of the earlier displays and even some current ones, including projectors,
only offer a single HDMI input. As a result, HDMI video switchers emerged to allow
user to easily switch between HDMI-capable components. Atlona Technologies, a
subdivision of Lenexpo Electronics, has created the AT-HDMI41, a new 4-to-1 HDMI
video switcher designed to switch between four HDMI sources. The AT-HDMI41 includes
an IR remote and provides an RS232 interface that allows an external controller
to command the unit. The construction of the AT-HDMI41 is solid with a fully metal
chassis that measures a moderate 9.5" W x 4.25" D x 2" H in size.
The front panel of the AT-HDMI41 has six LEDs and two buttons.
The Input button cycles through each of the HDMI inputs with the corresponding
LED indicating the active channel. TheSignal Enhance button on the right
side with the yellow LED indicator provides additional amplification to boost
the HDMI signal in the event longer cables are used with the switcher. This is
a common problem with many of the longer passive cables available today.
The rear panel of the AT-HDMI41 has the four HDMI input connectors
and the single HDMI output connector. The RS232 interface and power jack are also
found here. Powered by an external universal (100-240VAC, 50/60Hz) high-efficiency
switching AC power adapter, the AT-HDMI41 is supplied with 5V at up to 2.6A. The
9-pin RS232 connector allows the unit to be controlled from an external unit such
as a PC or high-end controller.
The AT-HDMI41 uses a trio of Texas Instruments TMDS341A switching devices cascaded
into two levels to handle the four HDMI inputs. This approach works well and the
performance of the devices is excellent in this unit. Control of the switches
and the RS232 interface is handled by a onboard SyncMOS SM8952A processor with
external EEPROM for nonvolatile storage. We found that even if power is removed
from the unit, the last configuration state is saved and will be restored when
the unit is powered on again. Many products will simply go back to a default setup
when power is interrupted. This was an impressive feature that we found by accident.
had three HDMI sources routed through the AT-HDMI41 switch for testing. Our Dish
Network ViP622 HD receiver, Toshiba HD-A1 HD-DVD player, and an OPPO Digital OPDV971H
DVD player all fed the inputs of the switch. The video output from the AT-HDMI41
switch went through a long 25-meter Atlona (AT14030-25) active HDMI cable, eventually
making it to our Mitsubishi HC5000 projector. This cable is an astonishing 82-feet
long and delivered error-free video to our projector. We had a variety of high
definition content from both the ViP622 and HD-DVD player and scaled up (1080i)
video from the OPPO OPDV971H DVD player. Video looked fantastic with excellent
resolution from our high definition sources. All video was in the form of 1080i,
so we didn't push the switch to the 1080p barrier. However, we did try the same
Atlona (AT14030-25) active HDMI cable directly from our Sony PlayStation3 to the
HC5000 projector and the video looked stunning in 1080p.
The AT-HDMI41 comes with an IR remote (CR-22) to select the
input channel and to power the unit on and off. This small remote looks similar
to the ones supplied with typical camcorders. Unfortunately, they do not appeal
to me because they are small and not agronomic. Fortunately, most universal remotes
can be programmed with the needed IR commands without a problem.
If the user has a more sophisticated setup in their viewing room, the rear RS232
interface can be used to control the unit. However, we could not find any documentation
that describes the serial interface such as baud rate, data size, stop bits, etc.
Thankfully, after inquiring we obtained a document that contained the needed information
(here). In our case, we have an RTI T4 controller
that can store virtually any IR remote code or send serial commands through a
wired interface. Either way, documentation is needed for this.
The Atlona AT-HDMI41 is a high performance HDMI switcher capable of solving the
problem of limited HDMI inputs. The performance we experienced with this switcher
gave us confidence that Atlona is capable of being part of our reference system
and meeting the demands of video enthusiasts. Furthermore, the retail price ($249)
of the AT-HDMI41 is very reasonable, making it highly competitive. The included
IR remote and RS232 interface gives the user options on how to integrate the switch
into their system.