Bidirectional communication enables the product to respond to data inquiries from the computer
and report back information, such as what type of print media is available or what accessories
are connected to the product. If the connection does not have this capability (that is, if it has no
bidirectional mode), it can only accept commands from the host and cannot report back
information to the host computer.
Bidirectional communication depends on your network operating system and on the type of
connection you have between your computer and your product.
When you install the HP Toolbox, bidirectional communication is always enabled. Installing
the HP Toolbox activates the HP Network Registry Agent (HPNRA) to ensure constant
communication between your computer and the product. When you install a driver without
installing the HP Toolbox at the same time, bidirectional communication is enabled only to
configure the driver, and is then disabled unless the driver's Update Now feature is used to
update the driver.
Enterprise AutoConfiguration
Enterprise AutoConfiguration (EAC) uses bidirectional communication to provide
autoconfiguration functionality for installation of the print driver over a network, whether you
use the installer on your printing-system software CD or the Add Printer wizard to install the
driver. Driver installation that includes EAC is configured with the same settings as the
physical configuration of the device. Configuration occurs without user interaction. If
bidirectional-communication software has been installed previously, EAC is not activated,
and the the pre-existing bidirectional-communication software is used to configure the print
driver.
If bidirectional communication software has not been installed, EAC installs bidirectional-
communication software that allows it to communicate with the product and automatically
match the print driver with the actual product configuration. EAC is activated during
installation of the driver or whenever the Update Now feature is used.
If the configuration of the HP Color LaserJet 4650 printer changes after installation, the
driver can be automatically updated with the new configuration in environments that support
bidirectional communication by using the Update Now feature. For example, if the
HP Color LaserJet 4650 is installed and an optional paper-handling accessory is added
later, you can use the Update Now feature to query the product and update the settings to
match the product's configuration.
If you are using an HP PCL or PS Emulation unidriver, you must select Update Now through
the Automatic Configuration setting in Device Settings tab. If you are using an HP
traditional PCL6 driver, you must click the Update Now button on the Configure tab. The
Update Now feature is not available with the HP Traditional PS Emulation driver.
The following tables show the availability of EAC for various operating systems and network
environments that support bidirectional communication.
Note
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