MODBUS Remote Terminal Unit (RTU)

Client Background


The client is a leading player into Oil & Gas, Power and Solar & Energy Management Systems. The client also has diverse business interests with subsidiaries in Automotive systems, IT, Infrastructure and Pharmaceuticals industry.

Project Information:


MODBUS based RTU are ideal for wide variety of distributed I/O applications including data acquisition, control, process monitoring, and test & measurement. The client was looking to build an RTU supporting variety of digital and analog inputs and outputs. The brief requirements specifications shared were:

  • Microcontroller based system
  • System to be designed for industrial environment
  • Digital Inputs: 16-ch single contact Isolated Inputs (with 4KV Isolation and Over Voltage protection)
  • Analog Inputs: 8-Ch Universal Analog inputs (Single ended and differential) supporting different types of signals like: 0 to 20 mA, 4 to 20mA, 0 to +10VDC, -20 to +20mA, -5 to +5VDC
  • Software selectable Analog Input range with 10ksps sampling rate, 250uS scan time for all channels, 0.05% Linearity, 95dBm CMRR
  • Surge and ESD protection on all Digital Inputs
  • Digital Outputs: 16-ch Single Contact Relay Outputs or 8-ch complementary contact outputs, Relay ON/OFF time ranges from 0.1 seconds to 60 seconds



Client chose Teq Diligent based on our understanding of Industrial Automation System Design and past record of delivering designs successfully. We owned the complete product development activity and delivered end-to-end solution including hardware design, firmware, prototype, testing & validation within the stipulated schedule. The solution included:

  • Renesas MCU (RL78 Series) Based Design
  • Small form factor to meet customer’s end-product specs
  • Designed to meet industrial environment with ESD/ Surge protections and Isolated power supply design



Teq Diligent worked with customers engineering team to deliver the project in time and helped customer go-to-market much faster. The design was turned around in first pass without any re-design/ testing efforts meeting the cost targets.

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