^SR - Set Printhead Resistance
Tells the printer the printhead's electrical resistance so it can compute burn energy.
^SR tells the printer the electrical resistance of the fitted printhead, which
the firmware needs to turn a darkness setting into a burn time. The value appears
on the printhead itself, and the guide warns that a value higher than the
printhead's own rating can damage the head.
Syntax
^SR####Support
Accepted and skipped, because it configures the printer rather than the label. It cannot change the rendered output, and Labelary skips it too.
The command feeds the printer's thermal energy model. The renderer draws a pure black-and-white raster with no energy model. The renderer does not parse this command. It reports IGNORED_COMMAND at info severity, which does not reach X-Warnings. Labelary is also silent, so the rendered label is identical in both engines. — not pinned by a test
Labelary renders this command.
Parameters
####Resistanceoptional · integerPrinthead resistance in ohms, as a four-digit value from the label on the printhead. The guide warns that a value above the printhead's rating can damage it. Newer models set resistance automatically.
- Default
- the last permanently saved value
- Accepted range
- 488 to 1175 ohms
- Invalid value
- not documented, and we have not measured it. The renderer does not parse or measure this command.
- Test coverage
- No test at the minimum, maximum or one step outside the range.
Behavior
It is not a darkness control. ^MD and ~SD adjust darkness; ^SR calibrates the
scale those settings apply against. An operator sets it once at a printhead
replacement and then leaves it alone. Newer printer models read the resistance
themselves and do not need it.
The renderer output is a black-and-white raster with no thermal model, so a
resistance feeds into nothing. The renderer ignores this command, and the darkness
commands are equally inert — see ~SD.
Example
A 500 ohm printhead declared, written as the guide's four-digit value:
^XA
^SR0500
^FO50,50^A0N,30,30^FDHead resistance^FS
^XZ
Related commands
~SDSet DarknessSets the base print darkness level.^MDMedia DarknessAdjusts print darkness up or down from the level `~SD` set.^JUConfiguration UpdateSaves the printer's current settings to non-volatile memory, or reloads saved or factory settings.