A communication system for operating in a process control environment, comprising: a remote device (16, 202, 302); an EMI reduction circuit (34, 204); a field device connected to the remote device (16, 202, 302) and a process control network, wherein the field device communicates with the remote device (16, 202, 302) via a first communication link (30, 224, 320) and with the process control network via a second communication link, the first communication link having a plurality of electrical wires (32A-32C, 214, 216, 218, 310, 312) capacitively coupled to the case ground potential of the field device by the EMI reduction circuit (34, 204), the process control network having a circuit ground that is a floating ground with an electric potential expected to vary relative to ground; and a signal processing circuitry to perform a physical step in the process control environment, the signal processing circuitry having a plurality of inputs coupled to the plurality of wires (32A-32C, 214, 216, 218, 310, 312), respectively, of the first communication link; characterized in that the communication system further comprises a common-mode noise reduction circuit (36, 210, 330) coupled to the first communication link (30, 224, 320) to reduce common-mode noise generated in the first communication link (30, 224, 320) as a result of a modulation of a signal on the first communication link relative to the circuit ground, wherein the modulation results from a voltage difference between the floating circuit ground potential and the case ground potential of the field device; wherein, to reduce the common-mode noise, the common-mode noise reduction circuit (36, 210, 330) is arranged to match input alternating current impedance on two or more of the plurality of electrical wires (32A-32C, 214, 216, 218, 310, 312) at two or more of the plurality of inputs, respectively, of the signal processing circuitry by increasing or decreasing the AC impedance on at least one of the plurality of electrical wires relative to the floating circuit ground potential of the field device. a remote device (16, 202, 302); an EMI reduction circuit (34, 204); a field device connected to the remote device (16, 202, 302) and a process control network, wherein the field device communicates with the remote device (16, 202, 302) via a first communication link (30, 224, 320) and with the process control network via a second communication link, the first communication link having a plurality of electrical wires (32A-32C, 214, 216, 218, 310, 312) capacitively coupled to the case ground potential of the field device by the EMI reduction circuit (34, 204), the process control network having a circuit ground that is a floating ground with an electric potential expected to vary relative to ground; and a signal processing circuitry to perform a physical step in the process control environment, the signal processing circuitry having a plurality of inputs coupled to the plurality of wires (32A-32C, 214, 216, 218, 310, 312), respectively, of the first communication link; the communication system further comprises a common-mode noise reduction circuit (36, 210, 330) coupled to the first communication link (30, 224, 320) to reduce common-mode noise generated in the first communication link (30, 224, 320) as a result of a modulation of a signal on the first communication link relative to the circuit ground, wherein the modulation results from a voltage difference between the floating circuit ground potential and the case ground potential of the field device;