See a note about power-over-Ethernet (POE) in Section 2.3.
The UE9 has a 10Base-T Ethernet connection. This connection only provides communication, so power must be provided by an
external power supply or USB connection. The UE9 ships with an Ethernet patch cable that would normally be used to connect to a
hub or switch. A direct connection from the UE9 to a computer might require a crossover cable (not included), but often the
network interface card (NIC) on modern computers is capable of automatically detecting the signal orientation and will work with
either cable type (patch or crossover).
The LEDs on a switch/hub/NIC can be used to determine if you have an electrically valid connection. An orange LED is often used
to indicate a good 10Base-T connection, but consult the manual for the switch/nub/NIC to be sure. In the case of a direct
connection between PC and UE9, if Windows says “A network cable is unplugged” or similar, it suggests that the UE9 is not
powered or the wrong type of cable is connected.
Complex networks might require the assistance of your network administrator to use the UE9, but the following information is often
sufficient for basic networks.
One basic requirement for TCP communication is that the UE9’s IP address must be part of the subnet and not already used.
Open a command prompt window and type “ipconfig” to see a listing of the IP address and subnet mask for a particular PC. If the
PC shows a subnet mask of 255.255.255.0, that means it can only talk to devices with the same first 3 bytes of the IP address.
The default IP address of the UE9 is 192.168.1.209, which will generally work on a network using the 192.168.1.* subnet (unless
another device is already using the .209 address). If the IP address of the UE9 needs to be changed, the easiest way is via USB
with the LJControlPanel application.
LJControlPanel and Ping (open a command prompt window and type “ping 192.168.1.209”) are useful utilities for testing basic
Ethernet communication. It is a good idea to attempt to Ping the desired IP address before connecting the UE9, to see if anything
is already using that address. A more extensive Ethernet troubleshooting utility called UE9ethertest is available. See the file
readme.txt in the UE9ethertest.zip archive for more information.
2.3 - Vext (Screw Terminals and Power Jack)
There are two connections for an external power supply (Vext): a two-pole screw terminal or a 2.1 mm center-positive power jack.
These connections are electrically the same, so generally only one is used at a time.
The nominal power supply voltage for the UE9 is 5 volts. Power can be provided from the USB connection (Vusb) or an external
power supply (Vext). The UE9 has an internal semiconductor switch that automatically selects between Vusb and Vext. Both power
sources can be connected at the same time, and either can be connected/disconnected at any time. As long as one supply
remains valid, the UE9 will operate normally. If both Vusb and Vext are connected and valid, the internal switch will select Vext.
The UE9 power supply requirement is nominally 5 volts at <200 mA (see Appendix A). This is generally provided by a wall-wart or
wall-transformer type of supply. A supply capable of 500 mA is recommended. The power jack connector is 2.1 × 5.5 mm, center
positive. A linear (regulated) or switching supply is acceptable. Switching supplies are generally noisier than linears, but the UE9
is not particularly sensitive to power supply noise, and most users will not notice any difference. One option is the CUI
EMSA050120K-P5P-SZ available from Digikey, for which you will also need a clip: EMS-AU (Australia), EMS-CC (China), EMS-
EU (Europe), EMS-UK (United Kingdom), or EMS-US (United States).
Another interesting option is a power-over-Ethernet (POE) adapter. The UE9 does not support POE itself, but there are POE
adapters that split out the data and power in such a manner that is acceptable for the UE9. These adapters consist of an injector
and splitter, and a single Ethernet cable carries data and power between the two. LabJack Corporation has done testing with the
WAPPOE unit from Linksys, which is an off-the-shelf POE adapter with the proper connections for a UE9.
2.4 - Comm and Control LEDs
There is a yellow LED associated with the Comm (communication) processor, and a green LED associated with the Control
processor.
The Comm LED flashes on reset and USB enumeration, and then only turns on when there is communication (USB/Ethernet)
traffic. This LED then turns off if there is no communication for about 200 ms.
The Control LED normally blinks continuously at about 2.5 Hz. In flash programming mode it blinks at about 8 Hz. If the LED is
blinking at about 0.5 Hz, that signifies the deprecated (no longer supported) low power mode. Those blink rates apply when the
UE9 is idle, as this LED also flashes on Control processor activity.
Normal Power-Up LED Behavior: When the USB cable is connected to the UE9 (no other connections at all and no software
running), both LEDs will start blinking. The Comm LED will blink a few times and then turn off. The Control LED will continue to
blink continuously.
2.5 - GND and SGND
The GND connections available at the screw-terminals and DB connectors provide a common ground for all LabJack functions. All
GND terminals are the same and connect to the same ground plane. This ground is the same as the ground line on the USB
connection, which is often the same as ground on the PC chassis and therefore AC mains ground. This ground is also the same
as the ground on either Vext connections (wall-wart power jack or minus screw terminals), but if an isolated supply is used, such as
the one included with the UE9, there is no common connection to AC mains ground.
SGND is located near the upper-left of the device. This terminal has a self-resetting thermal fuse in series with GND. This is often
a good terminal to use when connecting the ground from another separately powered system that could unknowingly already share
a common ground with the UE9.
The UE9 has separate ground planes on the PCB for analog and digital, but the planes are shorted together so the user only has
