What products are involved?
This article is based on using the SME (Smart Module Electronics) from SRV, SRD, DVP, and DVM.
What is the purpose of this article?
This article provides guidance on integrating the SME inline viscometer with a 3D TRASAR controller (Ecolab’s smart water management technology designed to monitor, control, and optimize industrial and commercial water treatment systems in real time) [1]
Figure 1. 3D Trasar diagram acting as a Modbus Master
Rheonics Type-SR sensors deliver robust, maintenance-free, Real-time, stable, repeatable, and reproducible measurements in Newtonian & non-Newtonian fluids, even in challenging environments, complementing the real-time monitoring and automation strengths of 3D TRASAR.
Supported protocols for Rheonics Type-SR include:
Modbus RTU (serial communication)
Modbus TCP/IP (Ethernet-based)
Analog 4-20 mA output
Profinet and Ethernet/IP
These communication options ensure flexibility to match the configuration and requirements of different 3D TRASAR system models.
1. Sensor Settings
The default configuration of the SME-TRD(Modbus RTU) using Modbus can be found in Table 1 below. The configuration can be modified using the RCP software (Figure 1).
Modbus parameters | |
| Slave ID | 1 |
| baudrate | 38400 |
| Parity | odd |
Table 1. Modbus default configuration parameters
Figure 2. RCP software and the communication tab are used for Modbus RTU configuration.
2. Recommended registers:
Sensor data is available in the input registers. Table below shows the commonly used registers.
Parameter 12 | Viscosity Last Good | |||
| 136 | 300137 | 2 | Float32 | Parameter 12 value as float |
| Parameter 13 | Density Last Good | |||
| 144 | 300145 | 2 | Float32 | Parameter 13 value as float |
| Parameter 2 | Temperature median | |||
| 56 | 300057 | 2 | Float32 | Parameter 2 value as float |
3. Where is the Modbus RTU RS-485 Port located?
The RS-485 interface is located between the power input port and the Ethernet port. It uses a 2-wire RS-485 configuration (RS-485-2W). The device does not include internal biasing or termination resistors, so proper RS-485 network setup—including external biasing and termination—must be ensured for reliable communication.
Figure 3. SME-TRD. Modbus RTU port.
4. 3D Trasar Controller Settings
4.1.Controller touch screen
Figure 5. Controller touch panel options.
4.2. Go to the configure menu and select the Modbus inputs option
Figure 6. Accessing the Modbus Data
4.3. Modbus inputs- Navigation menu
Figure 7. Modbus configuration menu
5. Wiring diagram 1
Variant 1 illustrates a straightforward connection between the RS-485 ports of both devices. The 3D TRASAR must be configured to poll data from the SME using the register addresses specified in section 2.
Figure 8. Wiring diagram 3D Trasar and Rheonics SME-Modbus RTU
6. Wiring 2- 2 SME into a single 3D Trasar
In this setup, both SME devices are connected to a single Ethernet switch, with one Ethernet cable running from the Ethernet switch to the 3D TRASAR. Each SME must be assigned a unique static IP address to ensure proper communication.
Figure 9. 3D Trasar with two Rheonics SME connected to an Ethernet switch. Option 2