KVM Switch Review
KVM Article: Troubleshooting KVM Dongles

KVM Switch Article
Troubleshooting KVM Switch Dongles

Raritan Z-Series 4200U
Single-User Cat5 KVM switch can control up to 42 servers in zero-U rack space, and is an inexpensive expansion option for Raritan's Paragon family of KVMs.
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KVM Switch Article: Troubleshooting KVM Switch Interface Modules

Technical Writer: Bob Pavlakovic

Interface Modules or also commonly referred to as Dongles were introduced as a way to reduce cable clutter by integrating CAT5 Cabling with KVM Switches. A Dongle simply hangs off a target computer’s Keyboard, Mouse and Monitor ports and converts those signals over to a CAT5 connection. Users will then connect a CAT5 UTP cable from the CIM and plug into a designated RJ-45 computer port on the CAT5 KVM switch.

To find out more about CAT5 KVM switches, please visit our CAT5 KVM switches page.

Unfortunately, Dongles can to be the root of several KVM switch issues. Interface Modules often are damaged during server migrations, their small size make for an easy wedge between cabinet doors, and dongles seem to travel from old servers to new more than most other data center accessories. Other times, Dongles have been known to fail all together without human interaction.

Some examples of KVM switches in which CAT5 cabling is used are Avocent’s AMX5000 KVM switch, the DX Matrix from Minicom, and the Raritan Paragon II.

Dongles are also integrated with Zero-U or Daisy-Chaining style CAT5 KVM switches. Zero-U CAT5 KVM switches use a Dongle in which 2 RJ-45 connections are utilized: an IN and OUT.

Instead of each Dongle connecting back to one individual port on the KVM switch, Zero-U Dongles connect to the next Dongle down the line by busing CAT5 cabling.

In order to straighten out problems that may arise with the growing segment of Dongle technology, below is a list of common troubleshooting techniques to get servers back on-line.

Problem:	Solution(s):
Dongle does not respond.	A fix as simple as replacing the CAT5/6/7 cable between Dongle and KVM can solve the problem.
	The Keyboard connection on the Dongle handles the power needed for it to work. Try unplugging just the keyboard port and then plug it back in. Rebooting the computer will most likely be needed afterwards.
	Try erasing information stored on the Dongle and then reboot the target computer.
	When a Dongle is plugged into a target computer, LED’s lights located next to the RJ-45 port are activated to show connectivity. One way to test whether or not the LED’s work is to hit your spacebar a few times while observing the troubled Dongle. The keyboard strokes will enable the LED’s to flash. If the LED’s do not flash, mostly likely there is a faulty CAT5 cable or Dongle.
	Damage to a Dongle can result by improperly powering on the target host. Please be sure to plug in the Dongle before booting the computer.
Video quality is blurred or displays a ghosting effect.	Some manufacturers offer a manual video adjustment knob located on the KVM switch box. Adjust this knob until the desired video quality is achieved.
	If long CAT5 cable runs beyond 200’ are used to connect the Dongle to the KVM switch, please check with the manufacturer to ensure the recommenced CAT5/6/7 cabling is used.
	Some manufacturers will require a user to implement shielded CAT5/6/7 cabling. Please reference the user manual to find out if your CAT5 KVM switch requires shielded cabling.
Firmware upgrade.	If old and new Dongles are mixed, often the KVM Switch itself will not recognize them. Please make sure the firmware is consistent throughout the entire KVM switch architecture. Firmware updates are available at our KVM Downloads page or from the manufacturer’s website.
Distance vs. Resolution	Resolution over a certain distance is very common question often asked about CAT5 KVM switches. Most vendors will place a chart in the user manual graphing out these specifications. Please reference the user manual for your resolution requirements.
Using non-certified CAT5/6/7 cabling.	From our experiences, standard KVM practices will allow for most brands of CAT5/6/7 to be used. However, if a user requires a high resolution or if a long distance from user to computer is needed, users should consider the recommended cabling to achieve the best results. CAT5/6/7 cable recommendations can be found in the user manual or by calling technical support.