MagTek Bluetooth MagneSafe V5 Swipe Reader - Manual (Page 29)

Section 5. Communications
21
Each command and response is composed of a series of readable ASCII characters followed by
the ASCII character CR (0x0D). The ASCII characters preceding the CR are the message.
There should always be an even number of characters and they should contain only the
characters 0123456789ABCDEF. The receiver will combine two successive ASCII characters
from the message to form one “byte” (see the descriptions of the commands) which may have
any value from 0x00 to 0xFF.
The following table shows the structure of a command message:
Byte Usage
0 Command Number
1 Data Length
2 – 23 Data
The following table shows the structure of a response to a command.
Byte Usage
0 Result Code
1 Data Length
2 – 23 Data
PRIVILEGED COMMANDS
Some commands are, for security purposes, privileged. Those commands are:
1. Set Property
2. Reset Device*
3. Set Security Level†
* The Reset Device command is usually not Privileged. The exception is during a sequence
to Activate the Authenticated Mode. During this sequence the Reset Device command is
Privileged to avoid a hacker using this sequence to exhaust DUKPT keys rendering the
reader unusable.
† The Set Security Level command is Privileged when it is being used to set the Security
Level. It is not Privileged when it is being used to Get the Security Level.
When the Security Level is set to higher than 2 (see the Security section), the privileged
commands must be MACed in order to be accepted. If a MAC is required but not present or
incorrect, RC = 07 will be returned.