The ZD621t is the ZD621 thermal transfer model that takes ribbon rolls, printing media 15-118 mm wide at up to 203 mm/s (8 ips) at 203 dpi. The ZD421t, which uses the same roll ribbon method, accepts only up to 112 mm, so if you need to print 113-118 mm wide labels with a ribbon, the ZD621t is the choice.
A media dancer, which the ZD421t does not have, keeps media roll tension even, so print quality stays consistent on each label and tag even at higher speeds. It takes ribbon rolls in two lengths, 300 m and 74 m, and the box contains one each 1-inch and 0.5-inch empty take-up core.
Print Quality menu on the touch display
A ZD621t with the 4.3-inch color touch display changes print method and media type on the display without a PC. The menu path is Print > Print Quality; the 2 items Print Type and Label Type can also be set with ZPL and SGD commands, and Label Length is view-only.
| Item | Settings | ZPL / SGD |
|---|---|---|
| Print Type | Thermal Transfer (uses ribbon), Direct Thermal (no ribbon) | ^MT / ezpl.print_method |
| Label Type | Continuous, Gap/Notch, Mark | ^MN / ezpl.media_type |
| Label Length | Displays only the length measured by calibration (dots), not editable | - |
When Label Type is Continuous (continuous media without gaps), the printer does not measure label length, so the layout must include a length in the 6.35-991 mm range (^LL in ZPL). With Gap/Notch or Mark, the printer measures label length itself while feeding media, and the measured length appears in Label Length in dots.
On models without a display, the same settings are changed in the driver or in the Media Setup menu of the printer web page.
Factory and field installation of the Wi-Fi 6 module
The 802.11ax (Wi-Fi 6) + Bluetooth 5.3 module is MIMO, using several antennas, when installed at the factory, and SISO when added later in the field. The 802.11ac (Wi-Fi 5) + Bluetooth module can be installed either at the factory or in the field, and Ethernet and RS-232 serial are in the unit from the start.
If you print only labels that do not use a ribbon, the ZD621 direct thermal model is lighter at 1.6 kg than the thermal transfer model (2.5 kg). Drivers are posted together with the direct thermal and RFID models on the ZD621 drivers and manuals page.
