RS485 Pressure Transmitter Solves VFD Interference Issue

Ever had a pressure transmitter that passed calibration but failed under VFD load? We traced a 25% pressure drop to electrical interference. The readings were fine at steady state, but every time the VFD ramped up, the signal dropped. This cost us thousands in lost production each month.

First, we reviewed maintenance logs. The problem wasn’t random noise—it was a design flaw. Each pressure sensor required a dedicated 4-20mA analog input card. Our PLC rack ran out of slots, forcing us to add expensive expansion racks at $150 per slot annually.

Then we discovered the DR3451 Pressure Transmitter with RS485. This RS485 pressure transmitter uses digital Modbus RTU communication. It connects directly to the PLC without analog input cards. Also, it supports multi-drop capability for up to 247 devices on a single port.

As a result, we daisy-chained all sensors on one PLC port. The Modbus pressure sensor eliminated slot limitations and reduced costs. The digital signal also provided high noise immunity, solving the VFD interference issue permanently.

For example, the installation was simpler—just a twisted pair cable instead of individual analog runs. The digital value transmission ensured accuracy without signal degradation. Therefore, we saved on hardware and maintenance costs.

Is your PLC rack running out of analog input slots? Consider a multi-drop pressure transmitter like the DR3451. It improves reliability and simplifies your system.

Key Specifications

• • Digital RS485 Modbus RTU communication

• • Direct PLC connection without analog input card

• • Multi-drop capability for up to 247 devices

• • High noise immunity

• • Digital value transmission

Tags: #RS485pressuretransmitter #Modbuspressuresensor #multi-droppressuretransmitter #DR3451