Compaq 99875320-5 Manual De Usuario
USB HID IntelliHead Swipe Reader
POLLING_INTERVAL PROPERTY
Property ID:
0x02
Property Type:
Byte
Length: 1
byte
Get Property:
Yes
Set Property:
Yes
Default Value:
10
Description:
The value is a byte that represents the devices polling interval for the Interrupt
In Endpoint. The value can be set in the range of 1 – 255 and has units of
milliseconds. The polling interval tells the host how often to poll the device
for card data packets. For example, if the polling interval is set to 10, the host
will poll the device for card data packets every 10ms. This property can be
used to speed up or slow down the time it takes to send card data to the host.
The trade-off is that speeding up the card data transfer rate increases the USB
bus bandwidth used by the device, and slowing down the card data transfer
rate decreases the USB bus bandwidth used by the device. The value of this
property, if any, will be sent to the host when the host requests the device’s
USB endpoint descriptor.
In Endpoint. The value can be set in the range of 1 – 255 and has units of
milliseconds. The polling interval tells the host how often to poll the device
for card data packets. For example, if the polling interval is set to 10, the host
will poll the device for card data packets every 10ms. This property can be
used to speed up or slow down the time it takes to send card data to the host.
The trade-off is that speeding up the card data transfer rate increases the USB
bus bandwidth used by the device, and slowing down the card data transfer
rate decreases the USB bus bandwidth used by the device. The value of this
property, if any, will be sent to the host when the host requests the device’s
USB endpoint descriptor.
This property is stored in non-volatile memory, so it will persist when the unit
is power cycled. When this property is changed, the unit must be reset (see
Command Number 2) or power cycled to have these changes take effect.
is power cycled. When this property is changed, the unit must be reset (see
Command Number 2) or power cycled to have these changes take effect.
Example Set Polling Interval property Request (Hex):
Cmd Num
Data Len
Prp ID
Prp Value
01 02
02
0A
Example Set Polling Interval property Response (Hex):
Result Code Data Len
Data
00 00
Example Get Polling Interval property Request (Hex):
Cmd Num
Data Len
Prp ID
00 01
02
Example Get Polling Interval property Response (Hex):
Result Code Data Len
Prp Value
00 01
0A
18