Section 4. USB Communications

SERIAL_NUM PROPERTY

Property ID:

1

Property Type:

String

Length:

0 – 15 bytes

Get Property:

Yes

Set Property:

Yes

Default Value:

The default value is no string with a length of zero.

Description:

The value is an ASCII string that represents the device’s serial number. This

 

string can be 0 – 15 bytes long. 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, if any, will be sent to the host when the host requests

 

the USB string 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. Examples follow.

Example Set SERIAL_NUM property Request (Hex):

Cmd Num

Data Len

Prp ID

Prp Value

01

04

01

31 32 33

Example Set SERIAL_NUM property Response (Hex):

Result Code

Data Len

Data

00

00

 

Example Get SERIAL_NUM property Request (Hex):

Cmd Num

Data Len

Prp ID

00

01

01

Example Get SERIAL_NUM property Response (Hex):

 

 

Result Code

Data Len

Prp Value

 

 

 

00

03

31 32 33

 

POLLING_INTERVAL PROPERTY

 

 

Property ID:

2

 

 

 

 

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

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Tyco 1529L manual Serialnum Property, Pollinginterval Property