Why is there no response or are the readings abnormal when connecting an RS232 pressure transmitter to a host computer? This article explains how to check the interface and power supply, verify TX/RX wiring, and configure the baud rate and parity. It also covers the Modbus protocol, register parsing, and common troubleshooting methods. For devices with analog outputs, it introduces a solution for connecting through a data acquisition module, helping engineers avoid blind spots during commissioning, quickly locate communication issues, and improve on-site integration efficiency.