Optical emission spectroscopy measurements and film deposition experiments were performed for better understanding and control of the plasmachemical vapor deposition (PCVD) process used in the coating production of Widia/Valenite. The effects of the titanium chloride flow, the nitrogen flow, the mean discharge current density and the pressure were investigated. The coatings were characterized with respect to deposition rate, composition, crystallographic structure and Vickers microhardness. In particular, the dependence on process parameters of emission signals (lines/bands) from 12 species (Ti, Ti+, Cl, Cl+, H-2, H, N-2, N-2(+), N, N+, Ar and Ar+) involved into the TiN deposition process was analyzed. Additional spatially resolved OES measurements of the 12 species revealed in particular that the emission of Ti+ arises only from near the cathode surface. Based on an empirical model it was shown that the emission of atomic titanium is related to the intrinsic titanium deposition rate whereas the emission of ionized titanium results from the etching of titanium not yet bounded to nitrogen from the surface.