Why is a T-NodeFR Not Detecting?

The NexSens T-Node FR User Guide outlines the required process for integrating a T-Node FR temperature sensor or string with a NexSens X-Series data logger. If one or multiple nodes along the string fail to detect after following the guide, below is a list of common reasons.

Issues During T-Node FR Detection

  • Issue #1: Two or multiple T-Node FR sensors (or other sensors using Modbus) have the same Modbus address.
    • Explanation: NexSens X-Series data loggers can only detect a T-Node FR if it has a unique Modbus address assigned. If another sensor using the Modbus communication protocol has the same address, both sensors will respond simultaneously to commands. Thus, communication will be interrupted as the logger expects a specific response.
  • Issue #2: The nodes within the T-Node FR string are not addressed in increasing numerical order.
    • Explanation: NexSens X-Series data loggers treat the complete T-Node FR string as a single sensor instead of each node as its own sensor. Thus, the first node should be the lowest address, and the last node on the string should be the highest. The internal script will begin with the first address and end when there is a break in the available addresses.
      • Solution: Check or change the Modbus address of each T-Node FR in the string. Ensure to note the serial numbers associated with each address to put the string together in proper order.