Abstract: A connector has conductive pins extending from outside the device to within the device and an electrically conductive wall surrounding a portion of the pins. The conductive wall abuts a printed wiring board containing EMI protective circuitry and contacts a ground plane within the printed wiring board. A selected pin is brazed to the connector and holds the printed wiring board in compression to assure a low impedance connection to the ground plane.

Abstract: A three wire transmitter bidirectionally communicates AC signals to and from a first external device and sends DC signals to a second external device. The transmitter includes a communication circuit which is energized from power and common terminals and includes memory storage for transmitter status and a process variable (PV). The communication circuit receives a sensor output indicative of the PV and provides the DC signal and the AC signal to a signal terminal which connects to both external devices, and also receives AC signals from the first external device. The communications circuit has a characteristic AC impedance between the signal and common terminals over an AC frequency range for receiving and transmitting AC signals to and from the first external device so that the receiving signals are not shorted out and so the transmitted signals can be received.