NexSens T-Node FR and TS210 temperature strings have an RS-485 Modbus output that allows direct connection to a Modbus master device (i.e. PLC). To connect the string, a UW receptacle to flying lead cable is required. These cables are available in lengths ranging from 1m to 100m.


Figure 1: UW Receptacle to Flying Lead Cable

The wiring for the T-Node FR or TS210 string to the Modbus master is shown in Table 1 below.

Table 1: T-Node FR/TS210 String to Modbus Master Wiring

Wire ColorSignal

* Wires not listed are not used and may be removed or tied off.

Register Information

Once connected, the following registers can be used to collect data and change the Modbus address of a node in the string.

Collect Data

Function 0x04 (Read input registers)
RegistersData TypeData SizePurpose
0x000632-bit Float, Big-endian2 registersRequests the temperature recorded by the node in Celsius


Example, collecting data from Modbus Address 1:

Collect Data
Field NameHexField NameHex
Slave Address0x01Slave Address0x01
Start Address Hi0x00Byte count0x04
Start Address Lo0x06Register Value Hi0x41
Quantity of register0x00Register Value Lo0xAF
Quantity of register0x02Register Value Hi0x38
CRC Lo0x91Register Value Lo0x1D
CRC Hi0x50

The response of 0x41 0xAF 0x38 0x1D converts to a Float value of 21.902.

Change Modbus Address

Function 0x10 (Write multiple registers)
RegisterData TypeData SizePurpose
0x100016-bit Integer1 registerChanges the Modbus Address of the node


Example, changing address from 1 to 5:

Change Modbus Address
Field NameHexField NameHex
Slave Address0x01Slave Address0x01
Start Address Hi0x10Start Address Hi0x10
Start Address Lo0x00Start Address Lo0x00
Quantity of register0x00Quantity of Outputs Hi0x00
Quantity of register0x01Quantity of Outputs Hi0x01
Byte count0x02CRC Lo0x05
Outputs Value Hi0x00CRC Hi0x09
Outputs Value Lo0x05
CRC Lo0x77
CRC Hi0x92

0x05 is the new slave address of 5.

Read T-Node FR ID

Function 0x04 (Write multiple registers)
RegisterData TypeData SizePurpose
0x100732-bit Integer, Big-endian2 registersReads the T-Node FR ID


Example, reading node with Modbus Address 1:

Read T-Node FR ID
Field NameHexField NameHex
Slave Address0x01Slave Address0x01
Start Address Hi0x10Byte count0x04
Start Address Lo0x07Register Value Hi0x00
Quantity of register0x00Register Value Lo0x10
Quantity of register0x02Register Value Hi0x01
CRC Lo0xC4Register Value Lo0x09
CRC Hi0xD7

The four bytes 0x00100109 represent the ID for the T-Node FR.

If the addresses of all T-Node FRs in a string are known, the address of a single node may be changed while it is in the string using the Change Modbus Address command above.

For T-Node FR strings configured by NexSens, the first node is assigned Modbus address 1 unless otherwise noted. Each successive node has a value one higher than the previous node (2, 3, 4, etc.). TS210 strings are always configured in this manner unless requested otherwise.

IMPORTANT NOTE: Use extreme caution when changing the address of a node in a TS210 string to ensure that the nodes remain in numerical order and the same address is not assigned to more than one node simultaneously.


 REV: 15B17

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