User`s manual

Alcorn McBride Digital Video Machine DVM-7400 User’s Manual Rev 1.5
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A: The DVM is capable of playing MPEG2 clips with a maximum bitrate
of 15mbps, however the Compact Flash card must be fast enough to do
this. Try using a newer compact flash card, or a compact flash card that
is rated for higher transfer speeds. If you are unable to do so, try
lowering the bit-rate of your MPEG encoding.
Q: I am trying to play an MPEG file on the DVM. I hear audio, but the
video output just looks like a bunch of random colors and blocks.
What’s happening?
A: The MPEG2 file that you are playing is most likely encoded with a
4:2:2 chroma format. The DVM only supports a chroma format of 4:2:0.
Change this setting in your encoder, and re-encode the video with the
correct format.
Q: Do you have a basic checklist I can go by in order to figure out what’s
wrong?
A: Here’s a checklist we have compiled of typical things you can check
to make sure all the bases are covered:
• Is the unit plugged in? (bear with us)
• Does the unit have a Compact Flash card in it at all? (remove
the front metal plate & check)
• Is the Compact Flash card pressed in all the way?
• Validate you’ve used the A/V cables somewhere else
successfully. Verify your display works, etc…
• If you are using a serial cable, is it straight through (as
opposed to a null modem)?
• Are your MPEG files MPEG2 Program Streams?
• Are your file name formats valid? See the File Names section
to be sure.
• Take every other piece of control equipment away from the
unit, making it stand-alone until you get it running. Try to make
it operates now either with contact closures (paper clips will
work) or serial commands from a laptop or PC.
• If the unit does not respond to serial messages typed by hand
or from another system:
o Have you validated you are communicating through
the serial port correctly? Chosen the right PC comm.
port? Using 9600, 8,N,1? If you want to validate the
comm. port is right, use a paperclip to short together
pins 2 and 3 on your computer’s serial port cable. It
should echo back to you the keys you type from a
terminal emulator like Hyperterminal.
o Are you using the correct commands listed in the
Command Protocol Section? Can you get a version
number from the box by using a terminal emulator, or
AMI Terminal?
• Is the Compact Flash Card damaged? Do you have a second
Compact Flash card you can temporarily use to make sure the
Compact Flash Card isn’t just damaged? Go through the file