CARMENES. IV: instrument control software Guardia, Josep Colome, Josep Ribas, Ignasi et al. Paper 8451-108 of Conference 8451 Date: Sunday, 01 July 2012 The overall purpose of the CARMENES instrument is to perform high-accuracy measurements of stellar radial velocities (1 m/s) with long-term stability. CARMENES will be installed in 2014 at the 3.5 m telescope in the Calar Alto Observatory and it will be equipped with two channels for spectroscopic data collection at near-IR and visible windows. The instrument coordination and management is handled by the Instrument Control System (ICS), which implements the CARMENES operational design and is responsible to carry out an efficient operation of the full instrument. We present the ICS architecture design and the APIs for low- and high-level communication.