Zebra Technologies TTP 7030 - Manual (Page 68)

Programming
Status Reporting 68
P1003636-002 TTP 7030™ Technical Manual 10/05/2009
Status Reporting
The printer is equipped with a number of sensors that report the printer status and various error
conditions such as out-of-paper, previous printout not removed, etc.
A good practice in unattended printer applications is to check for errors and paper availability
before printing.
1.
Send a Status Report Query (<ESC><ENQ><6>, see page 59 ) and check that the answer
is "No errors"
2.
If an error is indicated, read out the error message with Status Request
(<ESC><ENQ><1>, page ), and take appropriate actions. Repeat this step until no more
error code is available. If weekend sensor signals that paper is below this level, check
again after next document is printed. If the sensor still signals a level below the weekend
level after three successive print/check cycles, report the condition to the systems
supervisor so that he can schedule a service visit to the printer. This three-cycle check is to
ensure that dirt on the side of the roll does not cause the alarm.
3.
Send a paper-near-end query (<ESC><ENQ><2>, see page 57 ) to see if the sensor reports
low paper level.
4.
If paper-near-end is indicated, report the condition to the systems supervisor so that he can
schedule a service visit to the printer.
5.
Print the printout.
Important • A status reply must be read! Sending a second status query without reading the
reply of the first query may lock the printer.
Note • When using a multitask OS, status queries and responses may not be transferred
immediately from your application to the printer and vice versa. So write your program in
such a way that it repeats the query if it gets a timeout or an invalid reply. Good practice is to
ask once every 2-3 seconds, five times before giving up.
Note • You should construct your application in such a way so as not to request status while
printing, as this can result in loss of data.