No, the USB port on the Apple Airport Express is designed for memory sticks, it does not provide enough power for anything else. If the eDMX will cycle on and off the network (basically reboot every few seconds) that is an indication that it doesn't have enough power (current) and is the symptom when powered by an Airport Express. Use a standard USB phone charger (0.5A) instead.

This can be caused by having another software open that also uses ArtNet (which the config utility uses). Close any other software that uses ArtNet while running the eDMX Config Utility.

The DMXking devices are delivered with the network settings configured at the factory to these defaults:

DHCP (IP address assigned by a DHCP server/router on a network)

eDMX1
ultraDMX2

Static IP (192.168.0.X where X varies with the product)

eDMX2
eDMX4 (Pro, DIN, ISODIN)
LeDMX4

When connecting a device directly to your computer's ethernet adapter (Thunderbolt, USB, built-in), instead of via an existing network/router, it's recommended that you change both the DMXking device and your computer to static IP. The steps to do that are as follows (applies to both Mac and Windows with slight variations). Please note that if your computer has multiple network adapters (including WiFi) and a different adapter is already using 192.168.0.x then you must select a different subnet (192.168.1.x for example) for both the DMXking device and your computer. Substitute 0 to 1 in the instructions below.

Make sure you can communicate with the DMXking device in the eDMX Config Utility, it should show up in the node list, and once you select it you should be able to see the firmware version and serial number. If not, see the other FAQ articles here for troubleshooting tips. Note that the eDMX1 product is only powered via USB, you always need to connect it via Ethernet to communicate.
Select Static IP mode. The default IP address is in the 192.168.0.X range where X varies based on model. Change if necessary, but these steps assume the defaults are used.
Click Apply/Update network settings. The device will reboot and use its new IP address. Depending on your computer's configuration it may or may not show up in the node list right away. See next steps.
Close the eDMX Config Utility and go into your computer's network configuration (System Preferences/Network on Mac, Network Adapters on Windows) and change the IPv4 address from DHCP (default) to static IP (Manually on Mac), and use 192.168.0.100 with subnet mask 255.255.255.0 and leave gateway/router blank. Apply settings.
Re-open the eDMX Config Utility and verify that the DMXking device shows up in the node list, and that there are no warnings when you click on it.
You can now close the eDMX Config Utility and start using your intended lighting software, using either ArtNet or E1.31/sACN, making sure you select the appropriate network adapter in the software (applies to most lighting software).

The DMXking devices map universe id 1 to ArtNet address 0:0:0, which is the way most software does it. But Lightkey has fixed universe ids (the top buttons in the fixture patch screen) starting at 1, so when you're using sACN the first universe in Lightkey is sACN id 1, which maps to the first port on all DMXking devices using factory defaults. When you configure Lightkey to use ArtNet then the first universe will be ArtNet address 0:0:1. So if you want to use ArtNet in Lightkey then you need to configure the ports on the DMXking devices with starting universe id 2. Another aspect of using sACN is that the IP address of the DMXking matters less, since sACN by default is using multicast. When using ArtNet you have to make sure the DMXking device is in the same subnet (192.168.0.x for example) as the Mac's network adapter. In the standard for sACN (E1.31) the first address is 1, and in the ArtNet standard the first address is 0:0:0.

The DMXking devices always listen for both ArtNet and sACN/E1.31 data. Both protocols are perfectly fine to use, sACN is newer with advanced features like priority. ArtNet on the other hand has a discovery mode that is handy where you can scan the network to see what devices are available. ArtNet is also using broadcast where sACN is using multicast by default, however both protocols can use Unicast.

There are a few reasons for this, the most common ones are:

WiFi is enabled on Mac. This can cause the Mac to send out the discovery packets to find the DMXking device on the wrong network adapter. Try to temporarily disable WiFi while you configure the IP addresses for your set up.
A lighting software is running. The Config Utility is using ArtNet to communicate with the network-based DMXking devices. ArtNet in its design is limiting communication to one application per computer, so when a lighting software that uses ArtNet is running at the same time as the Config Utility then the last software to be launched won't be able to communicate with ArtNet. When running the Config Utility make sure all other lighting software are closed.
Firewall is blocking the ArtNet communication. Make sure all firewalls are temporarily disabled.
Incorrect IP configuration like wrong subnet mask, IP conflict (all devices need a unique IP address), wrong subnet (192.168.0.x vs 192.168.1.x as an example) or multiple network adapters using the same subnet (for example 192.168.0.100 on one adapter, 192.168.0.101 on another adapter).

Try to disable WiFi (temporarily) and then restart the Config Utility. Sometimes the mac gets confused on which network interface to broadcast the discovery packets (that are used to find the devices on the network). Then you can configure the IP settings and complete the configuration. Once you have the IP settings completed you can re-enable WiFi.

If you get an error when trying to open the eDMX_Configuration_macOS.pkg file that you downloaded from dmxking.com saying "can't be opened because Apple cannot check it for malicious software" then there is a way to open it. This applied to all software that aren't vetted by Apple. Instead of double-clicking the downloaded package, you right-click (two-finger click on trackpad, or hold down Control and single-click). Then select Open from the popup menu. You will now be able to select "Open" (it's grayed out, but can still be clicked) and install the software. This is due to a feature in MacOSX called GateKeeper.

The best way to get replacement connectors for the DMXking products is to buy them directly from electronics distributors like Digikey and Mouser. The DMXking distributors sometimes have a few spare connectors, so you can always check with them first.

MAX Devices

Articles for DMXking eDMX1 MAX

Frequently Asked Questions (FAQ)

MAX Devices

3-pin DMX port

2-pin power

4-pin pixel

10-pin IO port for LeDMX4

10-pin IO port for eDMX1 DIN and eDMX2