MagTek USB INSERTION READER - Manual (Page 30)

USB Insertion Reader
22
POLLING INTERVAL PROPERTY
Property ID: 2
Property Type: Byte
Length: 1 byte
Get Property: Yes
Set Property: Yes
Default Value: 2
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. This property is stored in non-volatile EEPROM
memory so it will not change when the unit is power cycled. The value of
this property will be sent to the host when the host requests the device’s
USB endpoint descriptor. When this property is changed, the unit must be
power cycled to have these changes take effect for the USB descriptor. If
a value other than the default value is desired, it can be set by the factory
upon request.
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