Some users rely on (a lightweight tool that creates a virtual COM port bridge). This is advanced but can solve persistent issues.
9600 (or 38400, depending on your cutting software requirements) Data bits: 8 Parity: None Stop bits: 1
A key feature of the Jk 721 is its versatile connectivity. It provides both USB and Serial (COM) ports, but the usability of these ports on a Windows 10 system heavily depends on the correct drivers. While many older plotters rely on serial connections, the Jk 721's USB functionality on modern operating systems is a primary area where users encounter difficulties. Jk 721 Cutting Plotter Driver Windows 10
Look under Ports (COM & LPT) . It should appear as "USB-SERIAL CH340" or "Cutting Plotter" assigned to a port like COM3 .
Windows has assigned a high COM port number, or another device is camping on the line. Some users rely on (a lightweight tool that
| Error Message | Cause | Solution | |---------------|-------|----------| | | Windows 10 blocks the JK 721 driver. | Disable driver signature enforcement (see section 4). | | “Device not recognized” | CH340 driver missing. | Download and install CH340 driver from WCH.cn. | | “Communication timeout” | Wrong COM port or baud rate. | Check Device Manager for correct COM port; match baud rate with plotter’s LCD menu. | | “Plotter does nothing” | Software sending wrong protocol. | Ensure software is set to HP-GL (not DMPL or other). | | “Cutting is distorted” | Speed/force settings or incorrect driver page size. | In driver properties, set page size to A4 or custom 720mm width . |
Windows 10 Enforcement blocks unsigned legacy drivers. It provides both USB and Serial (COM) ports,
Many users prefer CorelDRAW for design and want to send cut jobs directly from it.
| Setting | Value | |--------|-------| | | COM3 (or what Device Manager shows) | | Baud Rate | 9600 (default) or 19200 (check plotter’s LCD menu) | | Data Bits | 8 | | Parity | None | | Stop Bits | 1 | | Flow Control | None |
