TransCore AP4118, User Manual

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Configuring the AP4118 Rail Tag Programmer
14
AAR Tag Programming
Note: This information applies to AAR-compliant tag programming, with the permis-
sions tag settings as required to support AAR-compliant tag programming.
AAR-compliant programming requires validation and evaluation of some of the
incoming data, as described in the following section.
AAR User Data Type Detection and Format Delimiting
The AP4118 tag programmer supports only two basic AAR programming modes:
•
programming of rail tag as an AAR-compliant rail tag, or
•
programming of rail tag as an ASCII tag, according to the AAR Standard for
Automatic Equipment Identification (S-918) definition.
The programmer evaluates the incoming data as being in one of the two programming
mode categories, or responds with an error condition and prevents improper tag pro-
gramming. Upon receiving a legacy AP4110 Tag Programmer-compatible command,
the tag programmer evaluates the incoming user data to determine the data format
code (DFC) value as specified in AAR Specification S-918.
Table 3 lists the supported
DFC values.
If the DFC is any value not listed in Table 3 , the AP4118 creates an error condition
and #ERROR response, and tag programming stops.
AAR Rail Tag Security Character Handling
Upon receiving a legacy AP4110-compatible tag programming command, the AP4118
programmer checks the incoming security characters embedded in the user data. If the
incoming characters are secure, the AP4118 programmer then checks the secure char-
acters against the security characters in the permissions tag. The data remains the
same if a match is made; otherwise, an immediate data compare error occurs. This
error is due to security characters being replaced by space characters.
Table 3 Data Format Code, AP4118 Handling
6-Bit Binary
DFC Value
Value Definition
(per AAR Standard S-918)
AP4118 Handling
000000 6-bit ASCII format Allow programming; security character enforcement
required. Tag type handling not required.
110011 AAR-compliant: other; non-dynamic,
non-passive alarm; AAR/ATA/ISO Allow programming; enforce tag type and security
characters. (This is the predominant DFC value for a
rail tag.)
110100 AAR rail: toll road Allow programming; enforce tag type and security
characters