The following are types of device driver query messages:
Query Device Capability
This message is issued to a device driver by an application to query the basic capability of a device driver:
F0 00 00 3A 04 01 F7
The device driver responds to this message by returning a device capability response message (see Device Driver Response Messages).
Query Device ID
This message is issued to a device driver by an application to request the identity of the device driver:
F0 00 00 3A 04 04 F7
The device driver responds to this message by returning a device ID response message, which identifies the device (see Device Driver Response Messages).
Query Output Queue Size
This message is issued to a device driver by an application to request the size of the output queue:
F0 00 00 3A 04 02 F7
The device driver responds to this message by returning a queue size response message (see Device Driver Response Messages)