Programming instructions

Intermec Fingerprint v7.61 – Programmer’s Reference Manual Ed. 7 115
Chapter 2 Program Instructions
HEAD
Field of Application Function returning the result of a thermal printhead check.
Syntax HEAD(<nexp
1
>)
<nexp
1
> ≥ 0 specifi es the number of a dot for which the resistance in
ohms will be returned.
<nexp
1
> = -1 printhead check: Returns -1 (true) if OK
Returns 0 (false) if error
<nexp
1
> = -7 returns mean printhead resistance in ohms.
<nexp2> = HEAD(<sexp>)
<nexp
2
> returns the number (quantity) of faulty dots.
<sexp> returns the dot number and resistance for each faulty dot.
Remarks
This function allows you to examine the printhead in regard of dot resistance.
There is no guarantee that all defect “dots" will detected by the HEAD
function, since only the resistance is checked. For example, dirty or cracked
dots can only be detected visually.
The detection of a possibly faulty dot or printhead by means of the dot
sensing facility does not automatically imply that the printhead is defect
and that replacement will be covered by the warranty. Intermec reserves
the right of physical examination of the printhead before any replacement
free of charge can be discussed.
<nexp1> ≥ 0
A positive value specifi es a single dot on the printhead and returns its
resistance value as a number of ohms. A dot resistance value that deviates
considerably from the mean resistance value of the printhead (see below)
indicates that the dot may be faulty. The dot numbering starts at 0
(zero). This implies that in, for example, a 640 dots printhead, the dots
are numbered 0-639.
<nexp1> = -1
A check of the complete printhead is performed.
HEAD(-1)=-1 The printhead is within the allowed limits (no dot is
more than ±15% from the mean resistance value). This
does not guarantee the printout quality.
HEAD(-1)=0 A possible error has been detected.
<nexp1> = -7
The mean resistance value in ohms of all dots of the printhead is returned.
The second version of the HEAD function measures the dot resistance
for every dot in the printhead and faulty dots are reported to the system,
so you do not need to use a SET FAULTY DOT statement to report
bad dots one at the time.