Compax3 device description C3I22T1190 192-120114 N5 C3I22T11 June 20083.11.2. STO function on the Compax3MIn this chapter you can read about:Safety switching circuits .....................................................................................................90Safety notes and limitations of the STO function in the Compax3M ..................................91Technical details of the Compax3M S1 option ...................................................................923.11.2.1 Safety switching circuitsThe current flow in the motor windings is controlled by a power semiconductorbridge (6-fold IGBT). A processor circuit and PWM circuit will switch the IGBT withrotary field orientation. Between control logic and power module, optocouplers orpulse transmitters are used for potential separationOn the Compax3M drive controller with S1 option, the X14 (STO) connector can befound on the front plate. 2 optocouplers are controlled on two channels via theSTO1/ and STO2/ terminals of this connector. When requesting the STO via anexternal safety switching device, the two auxiliary voltage supply channels of thepower stage control circuits are switched off on two channels. Therefore the powertransistors (IGBTs) for the motor current can not longer be switched on.The hardware monitor detects a failure of the optocoupler circuit of a channel byalways checking both channels for similarity. If the hardware monitor detects adiscrepancy for a defined time (max. 20s), the error will be stored in the hardwarelatch The processor signals this error externally via the 0x5493 error code. An acti-vation of the coupler supply can then only take place via a hardware reset (swit-ching off and on again) of the device.*X14.4 STO_GNDX14.3 STO2/X14.2 STO-GNDX14.1 STO1/Hardware-Monitor+5V ControllerSoftware6 IGBTDriverPWMCompax3M ...S1* Potential separation with optocoupler.
