User manual

ScanVue5
®
Mini Kiosk
User Manual
M37574–01T
Industrial Electronic Engineers, Inc.
23-June-2008 Rev T Page 35
certain mode setting, it sends the command and the client will respond appropriately. If
not, an error report may be generated in response. Mode settings occupy a separate
name–space from the capabilities table. A mode setting could be used to change the
timeout value the client uses to decide that a socket connection has broken.
Error reports are used primarily as a debugging tool. The string starts with an error
number, optionally followed by white–space and explanatory text.
In the nominal case, messages consist of a length, followed by a token, possibly
followed by more information as specified by the length and the token. In the trivial
case, the message consists solely as a NUL–terminated text string; this is the case
when each of the four bytes of length field is an ASCII printable character. When such a
message is received by the server, it is interpreted as a product query; it optionally
contains the client’s identification and white–space preceding the product code. When
received by the client, it is interpreted as a single, textual response to a query.
Tokens Data Types
Terminate connection TERM No Operation NOP_
Capability query CAPQ Display Text TEXT
Capability CAPR Special Text SPEC
Mode set/query MDSQ UNC UNC_
Mode Response MODR URL URL_
Error Report ERR_ FIF FIF_
Product query PROD
Data DATA
Registration RGST
Event EVNT
Protocol Implementation Rules
1. Mode values changed during a query session are only retained during that session.
2. The host can make “permanent” changes to mode values for query sessions by
connecting to the ProductInfo protocol port (Port 1283) of the client and setting the
values. As long as that connection is maintained, the new values will be used in all
further queries.
3. Whether a “permanent change” will survive a power cycle of the client is
implementation dependent. Clients may provide special functions to record mode
information in non–volatile storage.
4. Query sessions are best kept limited to information that is to be displayed
immediately, so that further queries can be answered.
5. Mode values that start or end with whitespace must be sent enclosed in double
quotes. These quotes are removed when the value is stored. Double quotes within
the string are treated as part of the value.
6. When using double-byte font files such as the Kanji font (7640 characters), text
strings must be defined as Big-Endian or Little-Endian depending on the server.