In this paper the design of an implantable neural signal sensing system is described. The system is distributed with in the patient's body to allow a very low mass neural signal sensor to be placed at the optimum site for sensing with control of the sensor and external interfacing for power and data transmission in the abdominal cavity, where more space is available. A digital communication strategy between the two parts of the system is described, and shown to operate effectively over an implantable cable.