V740 RFID READER ANTENNA
NOTE. SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE. REV. 1.1
OPERATION MANUAL
21 of 27
© OMRON CORPORATION 2004
Use of RQL for Scheduled Reads
The V740 uses the Network Time Protocol as a
means to establish absolute time on the Reader. With
that capability in place the Reader is enabled to
execute tag operations that have been scheduled
relative to absolute time. Here is how it works.
First the user declares a cursor, or a set of cursors, in
a way similar to how to you use cursors in auto mode.
To run the query once at a specific time you use a
command of the form:
SET trigger_time <cursor list> =
'<time string>';
To run the query in auto mode over a given interval:
SET auto_time <cursor list> =
'<start time>';
or
SET auto_time <cursor list> =
'<start time>/<stop time>';
The first form here starts the auto mode at a given
time, and then just continues until you stop it, the
same way you'd stop normal auto mode.
The second form runs during the specified interval.
The cursor lists are the normal form of either 1 cursor
"cursor1" or a list of cursors, "cursor1, cursor2,
cursor3..."
The start and stop time are specified in ISO8601 time
strings, of the form
YYYY-MM-DDTHH:mm:SS.DDDDZZZZZ
Where YYYY is the year, MM is the month, DD is the
day, HH is the hour, mm is the minute, SS is the
second, and DDDD is the fraction of a second, and
ZZZZZZ is the time zone. The seconds and fractions
of a second are both optional (but if you want fractions
of a second, you have to have seconds as well). The
time zone can either be specified as GMT or Zulu time
by using a 'Z' or it can be an offset from GMT using
+HH:MM or -HH:MM. For us, in Eastern time, that
would be -05:00.
Some examples:
DECLARE c1 CURSOR FOR SELECT id FROM
tag_id WHERE antenna_id=1 AND
protocol_id='CC915';
DECLARE c2 CURSOR FOR SELECT id FROM
tag_id WHERE antenna_id=2 AND
protocol_id='ISO15693';
To run c1 once on February 14th 2004 at 18:54:50
GMT:
SET trigger_time c1 = '2004-02-
14T18:54:50Z';
To run c1 and c2 both for 10 seconds starting at 2004-
01-20 at 15:37 in Eastern Standard Time:
SET auto_time c1, c2 = '2004-01-
20T15:37-05:00/2004-01-20T15:37:10-
05:00';
Errors
If the Reader is unable to execute a command issued
by the Client Software, the Reader issues an error
message, which has the basic form:
ERROR error_code: string
where
error_code
is an integer. Error codes are
documented in Table 2.
For example:
DECLARE query1 CURSOR FOR SELECT id
FROM tag_id;
FETCH query2;
Would result in the error message:
ERROR 1 FETCH: Cursor does not exist