ModBus Strain Gauge Converter

DAT3025

ModBus Strain Gauge Converter.
ModBus Strain Gauge Converter

• ModBus RTU Slave.
• 4 Wire Strain Gauge.
• 6 Wire Strain Gauge.
• Digital Isolated Input.
• Digital Isolated Output.
• All way isolation.
General Description

The DAT3025 Modbus Strain Gauge Converter is designed for precise acquisition of analog voltage signals from 4 or 6-wire bridge transducers. It offers a configurable excitation voltage of 5V or 10V, ensuring compatibility with various transducers. Data transmission is handled via MODBUS RTU or MODBUS ASCII protocol over an RS-485 network, with an RS-232 interface model available upon request.
Key features of the DAT3025 include:

  • Alarm Thresholds:
    • Programmable SSR-type alarm thresholds for maximum or minimum values.
  • Digital Input:
    • Allows TARE weight functionality via a PLC.
  • Configuration:
    • Easily configurable using the Modbus_3000_10000 software.
  • DIN Rail Mounting:
    • Designed for efficient DIN rail assembly, maximizing space utilization.
  • Isolation:
    • 1500 Vac isolation between Strain Gauge input, power supply, RS-485, digital input, and digital output which eliminates ground loop effects.
  • Monitoring:
    • Communication activity LEDs for easy system monitoring.
  • Connectivity:
    • Removable screw terminals for input, output, power, and RS-485 connections simplify maintenance.
The DAT3025 complies with current electromagnetic compatibility directives and is housed in a robust, self-extinguishing plastic enclosure with a slim 22.5mm profile, ideal for high-density mounting on EN-50022 standard DIN rails.

INPUT OUTPUT POWER SUPPLY
+/- 30 mV. Bridge excitation 5 V +/-10% Power Supply Voltage 18-30Vdc
+/- 200 mV. Bridge excitation 10 V +/-5% Reverse polarity protection 60Vdc
Digital Tare 24Vdc. Trip Amp SSR 48 V max Reverse polarity protection 60Vdc
CURRENT CONSUMPTION CONFIGURATION ISOLATION
Between 0 mA DAT3000-10000 soft ware Between Input/Output/RS485/Power Supply 1500Vac.
EMC HOUSING TEMPERATURE
For Industrial environments Material self-extinguishing Operating Temperature 14°F +140°F -10°C +60°C
Immunity EN 61000-6-2 Dimensions W x H x T 4" x 4 3/4" x 3/4" Storage Temperature -40°F +185°F-40°C +85°C
Emission EN 6100-6-4 100 x 120x x 22.5 mm UL Operative Temperature 14°F +104°F -10°C +40°C
Weight 3 oz 90 g
DAT3025 Datasheet
Buy Online
Specifications
Drawings
DAT3025 User Guide
ModBus Analog Input Modules

User Instructions

Before installing the DAT3025, please read the “Installation Instruction” section. If the DAT3025 configuration is unknown, with DAT3025 switched off, connect the INIT terminal to the GND terminal (ground), reconnect the power and the DAT3025 will have the default settings (refer to the User Guide of the DAT3025). Connect the serial bus, analog, and digital inputs and outputs as shown in the “Wiring” section. The green “PWR” LED remains ON while power is connected, the yellow LED “STS” changes state and depends on the working condition of the DAT3025: refer to the "Light Signaling" section to verify the device working state. To perform configuration and calibration operations, read the instructions in the User Guide of the DAT3025. To simplify handling or to replace the DAT3025, it is possible to remove the wired terminals even with the device powered.
Specifications
Input:
Input Range Zero Span
+/-200mV -200 mV +200 mV
+/-30mV -30 mV +30 mV
Bridge excitation voltage (Vexc) R cell min R cell max
5 V +/-10% 150 Ω 10 ㏀
10 V +/-5% 300 Ω 10 ㏀
Max Bridge excitation current 50 mA
Sampling Time 200 ms
Resolution 16 bit
Input Accuracy the > of ± 0,1% f.s. or 5uV
Linearity ± 0,1% f.s.
Thermal Drift < 50 ppm/°C
Warm-up Time 3 min
ALARM TRIP AMPLIFIER – OUTPUT
Output Type SSR (solid state relay)
Output Contact SPST
Max Load (resistive):
Max Voltage 48 Vdc / 30 Vac
Max Current 0.4 A
Baud Rate Up to 115.2 Kbps
Maximum Distance 4000 ft 1.2 Km
Protocol Interface Modbus RTU Interface RS485 Modbus ASCII Interface RS485
Option RS232
Power supply voltage 20 .. 30 Vdc
Reverse polarity protection 60 Vdc max
Current Consumption 100 mA
Power Supply
RS485
Analog input
Analog output
Digital Input
Relays
 1500Vac 50Hz, 1 Min
Operative temperature 14℉ to 140℉
-10℃ to 60℃
-10℃ to 40℃
Storage temperature -40℉ to 185℉
-40℃ to 85℃
Humidity (not condensed) 0 to 90 %
Maximum Altitude 6500ft 2000m
Installation Indoor
Category of installation II
Pollution Degree 2
Weight 6 Oz
150 g.
Material Self-extinguish plastic
IP Rating IP20
Wiring size AWG 14-18
0.8÷2.1 mm²
Screw torque 0.8 N m
Mounting DIN rail standard EN-50022 and EN-50035
Dimensions H x" L x" T x"
H 100 mm L 120 mm T 22.5 mm
EMC For industrial environments
Immunity EN 61000-6-2
Emission EN 61000-6-4
Drawings

4 Wire Strain Gauge Input

4 wire strain gauge input wiring
Input.
Terminal 1 +Excitation
Terminal 2 +Vsense Connect to Terminal 5
Terminal 3 +IN
Terminal 4 -IN
Terminal 5 -Vsense Connect to Terminal 6
Terminal 6 -Excitation
When connectiong to a 4 wire Strain Gauge Connect Terminal 2 to Terminal 1, and Terminal 5 to Terminal 6.

6 Wire Strain Gauge Input

6 wire strain gauge input wiring
Input.
Terminal 1 +Excitation
Terminal 2 +Vsense
Terminal 3 +IN
Terminal 4 -IN
Terminal 5 -Vsense
Terminal 6 -Excitation
+Sense and +Sense can be used to compensate the resistance in the transducer cable.

Digital input

Digital input for ModBus Strain Gauge Converter

Digital IO


Input
Terminal 7 Terminal 8
Output SSR
Terminal K Terminal L

Input Voltage Off  0-3 V. On Status 10-30 V.
Output Solid State Relay.


Power Supply, RS-485 and Init

Power supply for the DAT3025
The DAT3025 ModBus Remote terminal unit is powered by 24 Vdc and can work with a tolerance between 20 and 30 Vdc. The ModBus RS485 signal is connected to terminal A and B. It is good practice to always use a shielded cable and earth the shield at one end of the coaxial cable.
If the DAT3025 configuration is unknown, and you can not connect to it you can use the INIT feature. With DAT3025 switched off, connect the INIT terminal to the GND terminal (ground), reconnect the power and the DAT3025 will have the default settings (refer to the User Guide of the DAT3025). Please note no IO will read or write with the INIT inserted.

Power Supply, RS-485 and Init


Power Supply
20 -30 Vdc Terminal J Positive Terminal I Ground
Init
Terminal D Init Terminal C Ground
RS-485
Terminal A D- Terminal B D+ Terminal C Ground
RS-232
Terminal E Tx Terminal F RX Terminal C Ground

Isolation Map

Galvanic Isolation layout for the ModBus Strain Gauge Converter
The Analog and Digital inputs and Outputs are all isolated from the power supply and the RS485 ModBus communication port.

LED Signaling


LED Color State Description
PWR Green On
OFF
Blink		 Power On
Power Off
Watch-Dog Alarm
STS Yellow Off Correct operation
RX Red Blink
Off		 Receiving Data
No Data Receiving
TX Red Blink
Off		 Send Data
Not Send Data
DI Red On
Off		 Digital Input On
Digital Input Off
DO Red On
Off		 Digital Output On
Digital Output Off
The DAT3025 has LED indication for different conditions. The Green LED is for Power Indication of the ModBus RTU IO Module. The Yellow is for the correct operation. The RX and TX red indication indicates sending and receiving the RS485 ModBus communication. The DI indication indicates that a Digital input has been seen and DO Led is indicating the Relay output has been activated.

The ModBus Strain Gauge Converter is suitable for fitting on to an EN-50022 top hat DIN rail in the vertical position. For optimum operation follow these instructions: Install the DAT3025 side by side. However, it may be necessary to separate them by at least 5 mm in the following case: Avoid temperature exceeding 45°C. Make sure that sufficient air flow is provided for the DAT3025 ventilation slits. Avoid mounting above appliances generating heat. Fit the DAT3025 in the lower part of the panel. Avoid high vibration. Don't route conductors near power signal cables such as motors, induction ovens, inverters, also use shielded cable for connecting signals.