A control valve positioner assembly configured to enable rapid exchange of a control valve positioner into and out of the assembly, comprising: a control valve positioner mounting device; and the control valve positioner, which is attachable to the mounting device, the mounting device comprising: a mounting portion including a base plate configured to receive the control valve positioner; and a manifold attached to the base plate and including: a first set of connection points configured to engage with corresponding ports of the valve positioner when the valve positioner is attached to the mounting portion, and a second set of connection points configured to connect to at least an air supply and a pneumatic actuator, the manifold thereby enabling the control valve positioner to be pneumatically connected to the air supply and the pneumatic actuator, the control valve positioner assembly being characterised by further comprising a back plate attached to a coupling side of the valve positioner and configured to engage with the base plate of the mounting portion, wherein the back plate includes a flange and the mounting portion includes a slot disposed between the base plate and at least a portion of the manifold, the flange being configured to be received within the slot when the valve positioner is mounted to the mounting portion and the ports of the valve positioner contact the first set of connection points of the manifold. a control valve positioner mounting device; and the control valve positioner, which is attachable to the mounting device, the mounting device comprising: a mounting portion including a base plate configured to receive the control valve positioner; and a manifold attached to the base plate and including: a first set of connection points configured to engage with corresponding ports of the valve positioner when the valve positioner is attached to the mounting portion, and a second set of connection points configured to connect to at least an air supply and a pneumatic actuator, the manifold thereby enabling the control valve positioner to be pneumatically connected to the air supply and the pneumatic actuator, the control valve positioner assembly being characterised by further comprising a back plate attached to a coupling side of the valve positioner and configured to engage with the base plate of the mounting portion, a mounting portion including a base plate configured to receive the control valve positioner; and a manifold attached to the base plate and including: a first set of connection points configured to engage with corresponding ports of the valve positioner when the valve positioner is attached to the mounting portion, and a second set of connection points configured to connect to at least an air supply and a pneumatic actuator, the manifold thereby enabling the control valve positioner to be pneumatically connected to the air supply and the pneumatic actuator, the control valve positioner assembly being characterised by further comprising a back plate attached to a coupling side of the valve positioner and configured to engage with the base plate of the mounting portion, a first set of connection points configured to engage with corresponding ports of the valve positioner when the valve positioner is attached to the mounting portion, and a second set of connection points configured to connect to at least an air supply and a pneumatic actuator, the manifold thereby enabling the control valve positioner to be pneumatically connected to the air supply and the pneumatic actuator, the control valve positioner assembly being characterised by further comprising a back plate attached to a coupling side of the valve positioner and configured to engage with the base plate of the mounting portion,