{"id":"iec-atan","model_id":"ATAN","name":"CODESYS ATAN","summary":"ATAN is an IEC operator in the CODESYS Development System that returns the arctangent of a number. The result is computed in radians. It can be written in ST (for example q := ATAN(0.5);) or placed as a block in FBD.","study_notes":["The result is computed in radians, not degrees.","Input variables that measure the angle in radians may be any numeric basic data type.","Output variables are permitted to be REAL or LREAL only.","Worked example: ATAN(0.5) gives the result 0.463648."],"safety_notes":[],"sources":[{"url":"https://infosys.beckhoff.com/content/1033/tc3_plc_intro/2529154955.html","title":"Beckhoff Information System","accessed":"2026-10-26"},{"url":"https://content.helpme-codesys.com/en/CODESYS%20Development%20System/_cds_operator_atan.html","title":"CODESYS Group","accessed":"2026-10-26"}],"verification":{"status":"source_checked","checked_at":"2026-10-26","values":3,"method":"llm_source_check"},"updated_at":"2026-10-26","type":"instruction","spec":{"language":"iec_61131_3","code":"ATAN","syntax":"q := ATAN(0.5);","parameters":[],"dialect":"CODESYS","related":[],"standards":[]},"url":"https://machineschema.com/instruction/iec-atan","license":"https://creativecommons.org/licenses/by/4.0/"}