J-Link PRO PoE

Quality assurance requires testing and when it comes to testing – more is better.

The power supply of test devices can be controlled remotely. This enables automated reboot for the testing process as well as the ability to turn off devices not in use, making it easy to build large-scale test farms.

The built-in web server makes manual configuration easy. Ethernet allows the use of the debug probe far away from the PC, over a hardwired or wireless network, in a development or production environment. It also makes download and debugging speeds higher and provides electrical isolation from the PC.

J-Link Pro PoE Network

Key features

  • PoE-enabled Ethernet interface
  • Switchable power out via USB-A or 20-pin header
  • Download speed up to 4 MB/s
  • Unlimited breakpoints in flash memory (Flash Breakpoints)
  • Use with Ozone, RDI/RDDI and J-Flash
  • Comes with web interface for easy TCP/IP configuration (built-in webserver)
  • Built-in VCOM functionality
  • Supports a broad range of microcontrollers
  • Supports direct download into RAM and flash memory
  • Free software updates

What is a test farm?

In terms of embedded systems, a test farm (or “board farm” or “device farm”) consists of a number of nodes (such as evaluation boards, prototype boards, production boards, finished products, etc.) connected to a network via debug probes, making them remotely accessible to testers or developers.

It is a very efficient way to share access to hardware that is in limited supply among a number of users. Additionally, automated build systems can run tests on the same standard setup, which is ideal for regression testing, continuous integration, compiler tests, and more.

Use Cases

There are a lot of use cases for almost any test setup for an embedded system. As soon as the number of devices to be tested grows, a test farm is inevitably required to ensure quality. A test farm using J-Link PRO PoEs may consist of multiple test devices of the same type or be completely different. We have described a couple of test cases below.

Communication tests

Communication reliability can only be tested with massive test setups that generates a huge amount of traffic on the communication channel. Specifically, wireless traffic, using protocols such as WiFi, ZigBee or Matter, is prone to interference and requires thorough testing in order to ensure operation even under bad conditions. Communication test setups therefore use heterogeneous targets to ensure interoperability with different devices as well as a huge number of similar devices to prove reliability.

Compatibility tests

Testing compatibility of an updated firmware module running on different platforms or of a compiler requires a setup using different devices. A test farm shortens test time by addressing the tests in parallel on multiple different targets and ensures, that any changes to the compiler or firmware module are tested thoroughly against all possible target devices.


J-Link PRO PoE features a PoE-enabled Ethernet interface as an alternative to the USB connection specifically to reduce the size of a cable harness in test farms.

J-Link Pro PoE Ethernet

Power & safety (galvanic isolation)

With PoE the J-Link PRO PoE can be powered and communicated with via a single interface. Target systems are shielded from power surges as the Ethernet signal lines provide galvanic isolation of the J-Link PRO PoE (and the target system) from the network and development PC.


Due to the Ethernet interface, it is easy to connect a large number of probes with long distances between the development PC and the target system. You can set a default gateway for J-Link PRO PoE making it also possible to use it in large intranets.

USB power source and delivery

Power is delivered to the target through a USB-A host connector (USB2.0, power-only). Power can be supplied from the USB interface of the J-Link PRO PoE with around 400 mA at 5 V. If the J-Linnk PRO PoE is powered over Ethernet, the power supplied can go up to 1 A at 5V.

J-Link Pro PoE USB Power Source


All software is included free of charge. It comes with licenses for all J-Link related SEGGER software products, such as J-Link Unlimited Flash Breakpoints, Ozone, RDI/RDDI, J-Flash, J-Link GDB Server, providing the optimum debugging solution for professional developers.


As a multi-platform solution, J-Link PRO PoE comes with the setup and control software for Linux, macOS and Windows. Software and firmware updates are included. Similarly, use on all currently supported target devices, and any that will be added, is also included.


J-Flash is a part of the J-Link Software and Documentation Package and allows the programming of the internal and external flash memory of a microcontroller-based embedded system via J-Link.


Up to 4 MB/s download speed make J-Link PRO the fastest debug probe on the market.

Flash Breakpoints

The J-Link PRO comes with an additional feature, called Unlimited Flash Breakpoints. Unlimited Flash Breakpoints allow the user to set an unlimited number of breakpoints when debugging in flash memory.

Ozone — The J-Link debugger

Ozone is the debugger for J-Link and J-Trace. It includes all well-known debug controls and information windows and makes use of the best performance of J-Link and J-Trace debug probes.

Standalone debugger

Ozone focuses on debugging. There are no compiler or project window distractions. All debug windows can be moved, resized and docked, to provide you with the workspace you need.

Ozone offers all well-known debug controls and information windows, and more. Instruction trace, power graph, live watches, and real-time terminal I/O further extend these capabilities.

J Link Pro Standalone Debugger

Performance analyzer

With J-Link’s High-Speed Sampling technology, Ozone can sample and visualize an embedded system’s variables over time. Checking values and flags in the debugger, while the target keeps running, is easy.

J-Link’s power measurement features enable you to record the power consumption of your target device in a debug session. This is especially helpful when you are developing a low-power device and need to know how power consumption changes when you enable or disable certain components.

J Link Pro Performance Analyzer

Technical specifications


Supported OSMicrosoft Windows (x86/x64), Linux (x86/x64/Arm), macOS (x86/Apple M1)
Electromagnetic compatibility (EMC)EN 55032, EN 55035
Operating temperature+5°C … +60°C
Storage temperature-20°C … +65 °C
Relative humidity (non-condensing)Max. 90% rH
Size (without cables)123mm x 68mm x 30mm
Weight (without cables)125g
Available interfaces
Ethernet interface100 Mbit/s
PoE supply voltagesIEEE 802.3af PoE type 1, class 3
USB interfaceUSB 2.0 (Hi-Speed)
Target interfaceJTAG/SWD 20-pin USB-A (power only)
JTAG/SWD interface, electrical
Target interface voltage (VIF)1.2V … 5V
Current drawn from target voltage sense pin (VTRef)< 25µA
Target supply voltage5V (when powered via USB)
5.25V (when powered via PoE)
Target supply currentMax. 400mA (when powered via USB)
1000mA (when powered via PoE)
Reset typeOpen drain. Can be pulled low or tristated
Reset low level output voltageVOL <= 10% of VIF
For the whole target voltage range (1.2V <= VIF <= 5V)
LOW level input voltage (VIL)VIL <= 40% of VIF
HIGH level input voltage (VIH)VIH >= 60% of VIF
For 1.2V >= VIF <= 3.6V
LOW level output voltage (VOL) with a load of 10 kOhmVOL <= 20% of VIF
HIGH level output voltage (VOH) with a load of 10 kOhmVOH >= 80% of VIF
For 3.6 <= VIF <= 5V
LOW level output voltage (VOL) with a load of 10 kOhmVOL <= 20% of VIF
HIGH level output voltage (VOH) with a load of 10 kOhmVOH >= 80% of VIF
JTAG/SWD interface, timing
Target interface speedMax. 50 MHz
SWO sampling frequencyMax. 100 MHz
Data input rise time (Trdi)Trdi <= 20ns
Data input fall time (Tfdi)Tfdi <= 20ns
Data output rise time (Trdo)Trdo <= 10ns
Data output fall time (Tfdo)Tfdo <= 10ns
Clock rise time (Trc)Trc <= 3ns
Clock fall time (Tfc)Trc <= 3ns
Analog power measurement interface
Sampling frequency200 kHz
Resolution50 uA

Package content

J Link Pro Poe
USB Cable
20Pin Target Ribbon

J-Link PRO PoE

USB cable

20-pin, 0.1″ target ribbon cable