The work considers the problem of automated diagnostics of the state of the anode steel pin of the Soderberg electrolyzer with an upper current supply, which is the main element of the current supply of the metallurgical unit. It is proposed to contactlessly control the shape and dimensions of the working part of the current-carrying pin using digital cameras. The images of the sections of the current-conducting pin, made in two mutually perpendicular planes, allowing to evaluate its shape and size. The possibility of using digital cameras with a resolution of 2 Mpx and 5 Mpx as recording devices is being considered. The error components of the control system of current-supplying rods located outside the electrolysis shop at the rod cleaning area are highlighted. The main attention is paid to the analysis of instrumental errors of the system. Possible configurations of the control system are considered and a method for compensating the main component of the error in non-telecentric optical systems - positioning errors is described.