eXtendo®
Thermal Printer Family
Part No. D-684-124
Mod. No. 4 270919 HW1
page 26 of 33
7.
Low Current Operation
There are numerous factors that affect thermal printer current. It is possible to manipulate these factors
consciously to reduce current draw for situations where this is important, such as operating from batteries.
If battery operation only occurs when power has failed, the host software can be programmed to print at a
faster, higher current rate during normal operation and then switch the eXtendo® to a lower current mode
when the system switches to battery operation. The following are some considerations to aid in reducing
current draw.
For all items described in the following, please refer to the eXtendo® Emulation Command Set
Reference D 684 112 or the eXtendo® Configuration tool for a comprehensive view.
7.1.
Print Speed
With thermal printers, average current is about proportional to print speed. Since the burn time for
each dot row is fixed, when printing slower there is more pause between burns and therefore a
lower average current. The eXtendo® target print speed can be set via command or the
configuration. The slower this print speed is, the lower the current draw will be. Note that when
printing via the eXtendo® Windows driver, print speed and density settings come from the settings
of the driver (see under “Devices and Printers”) and overrule the the printer internal settings.
7.2.
Graphics/Bar Codes
Printing graphics typically consumes more current than printing only text. Text-only printing is
considered to be ~15% coverage on average, while graphic or barcode printing may go up to 50%,
consuming 2x to 4x the average current. In terms of current draw, it does not matter whether
printing is done using the printer’s internal character set and barcodes or whether printing goes via
the graphical driver.
7.3.
Inverse Printing
Inverse text printing should be avoided when current matters, since everything that’s normally
black becomes white, and vice-versa, is drawing (in average text) about 6 to 8 times the current.
7.4.
Dot History Factor
Dot history monitors previously burned dots and reheats them for a shorter time to prevent
blooming and excessively black areas, thereby decreasing total current consumption. Using dot
history can help reduce average current draw but primarily increases print image sharpness.
7.5.
Multi-Strobe Factor
This feature is an eXtendo® software feature that will reduce
peak
current. When the double-burn
feature is turned on, only half of the printhead is fired at a time, reducing the peak current by
~30..40%, but having virtually no effect on average current. This is useful if your power supply or
connectors have a restrictive maximum current, but note that it limits the printspeed.
7.6.
Print Density Adjustment
Increasing print density will improve print quality / blackness, but at the same time will increase
current draw. Therefore Print Density is always a trade-off between these two characteristics. Use
the lowest print density that is visually acceptable to minimize current draw.
