zpl.tools
CommandsSensor calibration

^JT - Head Test Interval

Sets printhead element test interval

^JT - Head Test Interval

Overview

The ^JT command sets the automatic printhead element test interval from the default 100 labels to any desired interval (0-65535 labels). Allows customizing how frequently the printer performs diagnostics to balance performance with monitoring.

Syntax

^JT#

Parameters

  • # = Test interval in labels (0-65535)

Description

  • Configures test frequency
  • Default: 100 labels
  • 0 = Disabled
  • Testing during formatting

Examples

Test Every 250 Labels

^JT250

Disable Automatic Testing

^JT0

Test Every 50 Labels

^JT050

Considerations

Shorter Intervals (50-100)

  • More frequent monitoring
  • Catch problems early
  • Slight throughput impact
  • Best for critical operations

Longer Intervals (200-500)

  • Less frequent testing
  • Better performance
  • Later problem detection
  • For non-critical printing

Disabled (0)

  • No automatic testing
  • Best performance
  • No element monitoring
  • Risk of missing failures
  • ~JN - Head Test Fatal
  • ~JO - Head Test Non-Fatal
  • ^SR - Set Head Resistance

See Also