Magtek MagneSafe V5, Reference Manual

Page: 36 / 138

MagneSafe V5
28
Polling Interval Property (USB)
Property ID: 0x02
Property Type: Byte
Length: 1 byte
Get Property: Yes
Set Property: Yes
Default Value: 0x01
Description: The value is a byte that represents the reader’s 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
reader for card data packets. For example, if the polling interval is set to 10,
the host will poll the reader 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 reader, and slowing down the card data
transfer rate decreases the USB bus bandwidth used by the reader. The value
of this property, if any, will be sent to the host when the host requests the
reader’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. This
reader must be unplugged for at least 30 seconds to properly power cycle it.
Example Set
Polling Interval property to 10ms 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 01