Note
Unlike digital video interfaces, analogue interfaces like VGA do not detect when the monitor has been changed. They typically only detect the monitor and read the EDID on boot. Therefore, a reboot would be required to ensure that the host is reading the expected EDID. There are of course exceptions, particularly on some laptops where they do detect the presence of an external monitor.
Out of the box, each X-USBPRO Local unit has a built-in EDID that supports a default set of video resolutions. This is because it is not possible to transmit the EDID data back from the video monitor that is attached to the remote module to the computer’s video adapter. When the host computer boots, it reads the EDID directly from the X-USBPRO Local unit, which determines which video resolutions are available on its operating system.
To update the X-USBPRO Local unit with the actual monitors EDID, which may offer different resolutions, the monitor needs to be connected directly on to the X-USBPRO Local unit first so that it can be learnt.
Procedure
- Power on the Monitor
- Connect the Monitor to the VGA Out port on the X-USBPRO Local unit.
- Power on the X-USBPRO Local unit, this can be achieved in one of two ways:
- By connecting the USB cable to a host computer that is powered on, or
- By connecting an external PSU to the X-USBPRO Local unit.
- Watch the yellow LED on the CATX port of the X-USBPRO Local unit. This indicates the status when the unit tries to read the EDID from the monitor (see the Indications section below).
- Assuming that it was successful, disconnect the monitor from the local unit. This can now be attached to the Remote unit as per the manual.
- Reboot the host computer to ensure that it reads the new EDID from the X-USBPRO Local unit.
Note
If you have the X-USBPRO-MS2 multiscreen, you must do the same procedure for each video head on the local unit.
EDID Indications
Typical Responses
- If no valid DDC information is located, the yellow indicator will give one very short flash, representing an attempt to read data. No changes will be made to the information already stored within the local module.
- If the DDC information is the same as that already stored, no change will be made and the yellow indicator will give one single flash as the information is checked and normal operation resumes.
- If different DDC information is located, the yellow indicator will flash rapidly for 2 to 3 seconds while the new information is stored. A single flash will then be given as the information is checked and normal operation resumes.
Fault Responses
- Two flashes - Checksum error prior to copying - no information will be programmed.
- Three flashes - Too much data to fit into the module - the module can hold a maximum of two pages of DDC information.
- Rapid flashing followed by four flashes - data was lost during copying - the default data was substituted. Repeat the power on process.
- Rapid flashing followed by five flashes - Checksum error during copying - the default data was substituted. Repeat the power on process.