Intermec EasyCoder E4, Руководство программиста, Страница: 67 / 122

EasyCoder E4 Direct Protocol v2.10 – Programmer’s Reference Manual 65
Chapter 7 Reading the Printer’s Status
4. Printhead
5. System Counters
The thermal printhead can be tested in three different ways:
•
FUNCTEST$ ("HEAD")
•
? HEAD (type of check)
•
? SYSVAR (<parameter>)
? FUNCTEST$ (”HEAD”)
The returns from the FUNCTEST$ ("HEAD") command are:
HEAD OK, SIZE:nnn DOTS
(nnn is the number of dots)
HEAD LIFTED (lower the printhead and try again)
FAULTY PRINTHEAD (an error is detected)
? HEAD (<type of check>)
<type of check> = -1 Checks printhead. Returns -1 if OK, else
0 and sets up the printer for the measured
mean printhead resistance.
<type of check> = -7 Returns mean resistance of printhead in
ohms
Important!
Always either run a ? HEAD (-1) instruction after replacing the
printhead or print a test label to set the printer for the resistance
of the new printhead!
? SYSVAR (<parameter>)
<parameter> = 21 returns printhead density in dots per mm
<parameter> = 22 returns the number of dots in the printhead
There are a number of counters in the printer’s system, that can
be read and returned to the host:
? SYSVAR (<parameter>)
<parameter> = 14 number of errors detected since last startup
<parameter> = 15 number of errors detected since last
SYSVAR(15)
<parameter> = 24 power-up status since last SYSVAR(24)
(0 = No; 1=Yes)
SYSVAR(24)
is important, since essential functions, like coun-
ters and error messages will be lost at power up and other func-
tions will be reset to their default values. Save all such data in
the host and retransmit them to the printer as soon as a power-up
has been detected by a polling program taking advantage of
SYSVAR(24)
.