RS485 Pressure Transmitter Solves VFD Noise Issues

Ever had a pressure transmitter that passed calibration but failed during startup? We traced the issue to a VFD ramping up, causing a 20% pressure drop. Physics says each 4-20mA sensor needs its own analog input card at $150 each. Over time, racks filled with cards, and contamination caused recurring failures. We ran diagnostics and found significant noise from the VFD. Therefore, we switched to an RS485 pressure transmitter, the DR3451 Pressure Transmitter with RS485. This Modbus pressure sensor uses digital RS485 Modbus RTU communication, eliminating analog input cards. As a result, we reduced cards from 247 to just one, halving costs and freeing rack space. The multi-drop pressure transmitter connects up to 247 devices directly to a single PLC port without intermediate devices. Also, digital value transmission provides high noise immunity. First, the installation was straightforward. Then, the pressure readings stabilized. Now, the plant runs reliably. For example, similar facilities can upgrade to this multi-drop pressure transmitter to reduce costs and improve signal integrity. What’s the true cost per analog point, including cards, wiring, and terminations? Consider switching to digital for long-term savings. For more on noise immunity, see [Control Engineering’s guide on VFD noise](https://www.controleng.com/articles/vfd-noise-mitigation/).

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