1. Overview
The UNI-T UT685B KIT is a handheld TDR (Time Domain Reflectometer) cable tester designed for copper cables, including CAT 5E, CAT 6, CAT 6A, and CAT 8. It is used to detect and diagnose wiring conditions of twisted pair and coaxial cables, identify network services, and pinpoint issues like short/open circuits, split pairs, and miswires in network cabling. The device can also detect Power over Ethernet (PoE) supply and identify PoE standards (802.3AF, 802.3AT, 802.3BT).
The cable tester features a 2.8-inch LCD screen that simultaneously displays wiremap, cable length, open-circuit location, and other critical information. Its accurate, easy-to-operate, and visibly-displayed interface makes it an ideal tool for network communication maintenance, network engineering, and wiring engineering tasks.
2. Safety Information
To prevent fire, electric shock, or personal injury, please observe the following:
- Do not open the casing; there are no user-serviceable parts inside.
- Operate the tester strictly according to this user manual to avoid damage.
- Always check the tester before use. Do not use a damaged tester.
- Discontinue use if the tester does not function normally.
- Replace batteries immediately when the low battery symbol appears to ensure test accuracy.
3. Product Features and Components
The UT685B KIT offers a range of features for comprehensive cable testing and network diagnostics.
3.1 Main Specifications
- Display: 2.8-inch LCD (with backlight)
- Interface: Graphic interface
- TDR Support: Yes, no blind spot
- Cable Types: RJ11, RJ45, and coaxial cable
- POE: Standard identification
- Measurement Range: 500m (resolution: 0.3m)
- Scanning Mode: Supported
- Input Protection: 70V DC
3.2 UT685B TDR Cable Tester Components
- Wiremap adapter with 8-pin modular jack and coaxial F connector.
- 2.8 inch LCD display with backlight.
- Buttons (multiplexed) used to view test results.
- Select RJ45 or coaxial cable connector.
- Long press 2 seconds to turn on the meter; short press to turn it off.
- Mode knob: Wire tracking mode, testing mode, and POE mode.
- Short press to switch the unit, long press 1 second to turn on/off the backlight.
- Test mode indicator
- Numeric display with feet/meters indicator
- Tone mode indicator
- Detail screen indicator
- Terminal port indicator
- Tester icon
- Fault/high voltage indicator
- Wiremap indicator
- Ethernet port indicator
- Low battery indicator
- A wiremap adapter is connected to the far end of the cable
- Telephone voltage indicator
- Short circuit indicator
- POE indicator
3.3 UT683R Wire Tracker Receiver Components
- Antenna
- Charging status indicator light
- NCV button
- Wire tracking button
- Wiremap indicator light
- RJ45 jack
- Power button
- Flashlight button
- Sensitivity knob
- NCV indicator light
The UT683R receiver features adjustable sensitivity for accurate wire tracking. Adjust to weak sensitivity for strong signals and strong sensitivity for weak signals.
For noisy environments, the UT683R receiver includes a 3.5mm earphone jack, allowing users to wear earphones to avoid external interference during testing.
3.4 Power Supply
The UT683R receiver is powered by a 3.7V rechargeable battery and charges via a Micro USB cable (DC 5V, 1A). The UT685B TDR Cable Tester uses 3x 1.5V AA batteries.
4. Accessories
The UT685B KIT includes the following accessories. If any are missing or damaged, please contact your supplier.
| Item | Quantity |
|---|---|
| UT685B TDR cable tester | 1 pc |
| 1.5V AA alkaline battery | 3 pcs |
| RJ45 adapting cable | 1 pc |
| RJ11 adapting cable | 1 pc |
| RJ11 adapting cable (adapted to alligator clip) | 1 pc |
| Plug, F-connector to F-connector | 1 pc |
| User manual | 1 pc |
| Carrying bag | 1 pc |
| UT683R receiver (For UT685B KIT only) | 1 pc |
| Micro USB charging cable (For UT685B KIT only) | 1 pc |
5. Setup and Calibration
5.1 Powering On/Off
- Power On: Long press the power button (labeled '2' in Figure 3.2) for 2 seconds.
- Power Off: Short press the power button for 1 second.
5.2 Calibrating Length Measurements (Test Mode Only)
The tester calculates cable length using the NVP (Nominal Velocity of Propagation) and signal delay. While the default NVP is generally accurate, adjusting it to a specified or actual value can improve measurement accuracy.
- Enter the "NVP" value setting mode by holding down the "up arrow", "down arrow", and "ft/m" buttons simultaneously.
- To set the NVP for the coaxial port, please press "PORT".
- Find an Ethernet cable of known length.
- Connect the Ethernet cable to the tester.
- Use the "up arrow" and "down arrow" buttons to set the "NVP" value until the displayed length matches the known length of the Ethernet cable.
- To save the setting and exit NVP mode, power off the tester, then restart it.
6. Operating Modes
The UT685B KIT offers various operating modes for different cable testing and tracking needs.
6.1 Test Mode
In Test Mode, the UT685B can measure cable length, identify wire pairs, and troubleshoot faults like short circuits and split pairs.
- Turn on the tester and set the mode knob to "TEST".
- Press "PORT" to select either RJ45 or coaxial cable port.
- Connect the tester to the cable. For a complete wiremap test, connect the wiremap adapter to the far end of the cable.
The display will show the wiremap, cable length, and any detected faults. For example, if a wire is normal, the display will indicate "Wire is normal". If a twisted-pair wire is crossed and split, it will show "Split" and "Wire pair is wrong".
6.2 Wire Tracking Mode
This mode uses the UT683R receiver to track and locate cables.
- Connect the UT685B tester to the cable you wish to track.
- Set the mode knob on the UT685B to "SCAN".
- Use the UT683R receiver to trace the cable. Adjust the sensitivity knob on the UT683R to accurately locate the wire. A "Beep-Beep-Beep" sound indicates the tested cable is found.
This function is useful for both twisted-pair and coaxial cables.
6.3 POE Mode
In POE Mode, the UT685B can detect if there is Power over Ethernet supply and identify the POE standards.
- Turn on the tester and set the mode knob to "POE".
- Connect the tester to the network cable.
The display will show "POE" and identify the standard (e.g., af/at/bt) if connected to a power supply device using IEEE 802.3bt standard. The tester detects POE on pairs 1,2-3,6 and 4,5-7,8. The tester is designed to not be damaged by POE activation.
6.4 Tone Mode
In Tone Mode, the UT685B generates a 125KHz digital modulation signal (10VPP) which can be picked up by the UT683R receiver for wire tracking.
- Turn on the tester and set the mode knob to "SCAN".
- The default display shows the tone mode.
- Short press the "SCAN" button to enable or disable the hub blink function. If the tested cable is connected to a working switch, "CO" will flash synchronously with the switch port's indicator light.
6.5 NCV Voltage Detection
The UT683R receiver can detect non-contact voltage (NCV).
- Press the "NCV" button on the UT683R to enable the NCV function.
- If the voltage of the targeted cable or receptacle is greater than 40V (AC), the receiver will beep and the NCV indicator light will flash synchronously.
6.6 Flashlight Function
The UT683R receiver includes a flashlight for working in dark environments.
- Press the flashlight button on the UT683R to turn the flashlight function on or off.
7. Specifications
| Parameter | Value |
|---|---|
| Operating temperature | 0~45°C |
| Storage temperature | -20~60°C |
| Operating humidity | 20~75% RH (N.C) |
| Storage humidity | 10~90% RH (N.C) |
| Operating altitude | <2000m |
| Certification | CE, EN 61326-1:2013 / EN61326-2-2:2013 |
| Tester dimensions (UT685B) | 181mm*80mm*39mm |
| Receiver dimensions (UT683R) | 197mm*48mm*34mm |
| Test net weight (UT685B) | About 360g |
| Receiver net weight (UT683R) | About 127g |
8. Maintenance
- Cleaning: Avoid using solvent or corrosive cleaning agents as they can damage the display or casing. Wipe the display with a soft cloth and glass cleaner. Wipe the casing with a soft cloth dampened with clear water or liquid soap. Always keep the tester dry.
- Internal Access: Do not open the casing. There are no user-replaceable parts inside the tester. Opening the case without authorization will void the warranty and may damage the safety function.
- Replacement Parts: Use only designated replacement parts.
9. Troubleshooting
- Tester does not power on normally: Replace the batteries.
- Measurement length is inaccurate: Check the NVP setting and adjust it using a cable with a known length (refer to Section 5.2).
- Display or button does not respond: Power off the tester and restart it.
10. User Tips
- Screen Visibility: The screen offers corrected viewing angles, ensuring clear and well-visible information.
- Tone Generator: The tone generator is powerful, making wire tracking effective.
- Cable Length Accuracy: The device generally shows accurate cable length measurements.
- Flashlight: Utilize the built-in flashlight on the UT683R receiver for improved visibility in dark environments, such as server racks.
- Equipment Detection: The device is highly effective at identifying connected network equipment.
- Cable Location: The wire tracking function allows for precise cable location.
- Measurement Speed: While accurate, some users note that measurement speed might be slower compared to some other testers.
- Remote Connector Availability: If you need a spare remote side connector, check with your supplier or UNI-T's official support channels.
11. Warranty and Support
The product comes with a 1-year warranty. For any issues or support, please contact your supplier or refer to the official UNI-T website for further assistance.
For more information, visit www.uni-trend.com.