28440 Parallax Inc, 28440 Datasheet - Page 5

• Manufacturer Part Number: 28440
• Description: RFID Modules & Development Tools RFID Read/Write Serial Module
• Manufacturer: Parallax Inc

Specifications of 28440

• Operating Current: 10 mA
• Operating Voltage: 5 V
• Product: RFID Readers
• Wireless Frequency: 125 KHz
• Dimensions: 3.25 in x 2.45 in
• Operating Temperature Range: - 40 C to + 85 C
• For Use With/related Products: EM4x50
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

0x05: RFID_Protect
Enable (lock) or disable (unlock) the tag’s password protection.
Input: Mode (1 byte), 0x00 to unlock, 0x01 to lock
Output: Status byte (1 byte)
Example:
SEROUT RFID_TX, Baud, ["!RW", RFID_Protect, 1] ' Lock the tag
SERIN RFID_RX, Baud, [err]
Note: When the tag is locked, a successful login using the RFID_Login command is required before you
can enable/disable password protection, change the tag’s password, or read/write to the tag. If the tag is
locked and you are not successfully logged in, the RFID_Read command will return four bytes of 0x00 in
place of the actual user data and the RFID_Write command will return an error.
0x06: RFID_Reset
Log out and reset the tag.
Input: None
Output: Status byte (1 byte)
Example:
SEROUT RFID_TX, Baud, ["!RW", RFID_Reset]
SERIN RFID_RX, Baud, [err]
Note: All user data will remain stored on the tag. You will need to re-login using RFID_Login if you want
to access a locked tag after calling this command. You can also reset the tag by removing it from the
proximity of the RFID Read/Write Module.
0x0F: RFID_ReadLegacy
Read the 40-bit unique serial number from an EM Microelectronics EM4100 read-only tag (used with
Parallax’s RFID Card Reader Serial, #28140, and USB, #28340).
Input: None
Output: Header (1 byte) + data (10 bytes) + footer (1 byte)
Example:
SEROUT RFID_TX, Baud, ["!RW", RFID_ReadLegacy]
SERIN RFID_RX, Baud, [header, STR data\10, footer]
Note: The header and footer are used to identify that a correct string has been received from the
reader (they correspond to a line feed and carriage return characters, respectively). The middle ten bytes
are the tag's unique ID sent in a printable ASCII string. For example, for a tag with a valid ID of
0F0184F07A, the following bytes would be sent: 0x0A, 0x30, 0x46, 0x30, 0x31, 0x38, 0x34, 0x46, 0x30,
0x37, 0x41, 0x0D.
Copyright © Parallax Inc.
RFID Read/Write Module, Serial (#28440)
' Get status byte
' Reset the tag
' Get status byte
' Read EM4100 unique serial #
' Get header, data, and footer
v1.0 6/29/2010 Page 5 of 10