TMC series: FAQ and Troubleshooting guide

Troubleshooting

Temperature readings show incorrect polarity (negative when should be positive)

This indicates a wiring issue, commonly occurring when customers wire their own thermocouple sensors. 

Solution:

1. Verify your connections match the product’s connection diagram in the technical datasheet

Intermittent or sporadic incorrect readings

This typically results from temporary connection issues or environmental factors.

The good news is that you probably don’t have a problem with the sensor. All you need to do is improve your installation!  Indeed, most intermittent reading problems are resolved through improved connections or environmental modifications.

But of course, we can help you solve the problem. However, to save some time helping us identify the root cause, we ask our users to perform the following checks and share with us the results with their support request.

Cable Examination

• Inspect the entire thermocouple sensor cable for damage, kinks, or excessive bending
• Check for mechanical stress or movement during operation
• Note if the cable passes near moving parts or high-temperature areas

Installation Environment

• Is the setup subject to vibration (machinery, HVAC, building movement)?
• Are there temperature fluctuations where connections are made?
• Is there moisture or high humidity around connections?

Electrical Interference Check

• Are motors, welders, or other electrical equipment operating nearby?
• Do invalid readings correlate with specific equipment turning on/off?

Noise Suppression

• Try connecting to a USB hub with external power (computer USB power can be unstable)
• For users who have wired their thermocouples to the connector themselves: Check all wire connections and ensure screw terminals are tight
• Look for corrosion, discoloration, or loose wires

Isolation Test

• Connect a different thermocouple sensor to see if the problem persists
• Try your current sensor with a different reader (if available)

Connection Stability Test

• Monitor temperature readings while gently wiggling wires at connection points
• Note if this triggers invalid readings

Pattern Analysis

• Does the issue occur at specific times?
• Is there correlation with environmental conditions or nearby equipment?

When contacting support, please provide:

• The serial number of the instrument
• Your operating system (e.g., Windows 11, Mac OS, etc.)
• Your current version of DracalView
• The results of the above tests
• The age of the system installation
• Recent changes made to the installation or nearby equipment
• Photos of your connection setup (if possible)

DracalView doesn’t recognize my product

This typically occurs with VCP products (product codes starting with “VCP-“) that are in VCP mode, since DracalView for Windows only communicates via USB protocol.

Solution – Switch to USB mode

Option 1 (Recommended)

1. Download DracalView version 3.4.2 or later
2. Use the ProtocolSwitcher tool located in C:Program FilesDracal to switch to USB mode with one click

Option 2 (Alternative method)

1. Download and configure PuTTY following our step-by-step procedure
2.  Enter the command PROTOCOL USB in the terminal like shown in this example
   • Note: You won’t see characters as you type – this is normal behavior

Your question or issue is not covered here?

For additional support, please do not hesitate contact our technical team. We typically answer in less than 1 business day.