An apparatus to communicatively couple a field device (104, 106, 108) to a remote terminal unit, the apparatus comprising: a base rack for said remote terminal unit in a process control system; a first termination module to be inserted in a first termination slot of the base rack, wherein the first termination module is configured to receive wires that are communicatively coupled to said field device (104, 106, 108); and a first control module, separate from the first termination module, to be inserted in a first control slot of the base rack, wherein the first control module to be communicatively coupled with the first termination module via a first termination link that communicatively couples the first control slot to the first termination slot on a backplane of the base rack, wherein the first control module is configured to control communications with the field device (104, 106, 108), the apparatus is characterized in that: the first termination module includes a signal conditioning card connected between the first termination slot on the base rack and a terminal block, wherein the signal conditioning card includes a backplane connector to communicatively couple the first termination module to the backplane, wherein the terminal block includes termination points to terminate the wires from the field device (104, 106, 108), wherein the first control module is separable from the base rack without unwiring the wires from the termination points, wherein the terminal block is separable from the signal conditioning card without unwiring the wires from the termination points, and wherein the signal conditioning card is separable from the backplane without unwiring the wires from the termination points. a base rack for said remote terminal unit in a process control system; a first termination module to be inserted in a first termination slot of the base rack, wherein the first termination module is configured to receive wires that are communicatively coupled to said field device (104, 106, 108); and a first control module, separate from the first termination module, to be inserted in a first control slot of the base rack, wherein the first control module to be communicatively coupled with the first termination module via a first termination link that communicatively couples the first control slot to the first termination slot on a backplane of the base rack, wherein the first control module is configured to control communications with the field device (104, 106, 108), the apparatus is characterized in that: the first termination module includes a signal conditioning card connected between the first termination slot on the base rack and a terminal block, wherein the signal conditioning card includes a backplane connector to communicatively couple the first termination module to the backplane, wherein the terminal block includes termination points to terminate the wires from the field device (104, 106, 108), wherein the first control module is separable from the base rack without unwiring the wires from the termination points, wherein the terminal block is separable from the signal conditioning card without unwiring the wires from the termination points, and wherein the signal conditioning card is separable from the backplane without unwiring the wires from the termination points.