Sto Channel Operation - Copley Controls Xenus Plus Compact Manual

Xenus Plus Compact STO Manual
STO Channel 3 is ANDed with Channel 2 to disable the drive by disabling both the high and low side MOSFET
gate drives. Any of the three channels by itself is therefore sufficient to prevent the initiation of motion or halt
drive induced acceleration when the STO function is activated.
Each STO channel receives an input in the form of a voltage (typically +24 Vdc to energize and 0V or open to
deenergize) applied to STO_IN1 (+,-) and STO_IN2 (+,-). Note in figure 2 that STO_IN1 (+,-) drives two parallel
connected opto-coupler stages (Channel 1 and Channel 3). STO_IN2 (+.-) drives the opto-coupler stage for
Channel 2 only. Both STO inputs must be simultaneously energized in order for torque/force to be produced. To
achieve the rated SIL and PL capability, both STO inputs must be held simultaneously de-energized by the
larger system when the STO function is activated. In a typical machine application, each STO input is driven by
a +24 Vdc supply voltage switched through a safety relay. Note that the STO inputs are designed to withstand
input voltages to +60 Vdc to provide a measure of overvoltage protection. By definition, the output of an SELV
rated power supply is a maximum of +60 Vdc in a fault condition. Therefore a constraint on the larger system is
that the power supply used to energize the STO inputs must be an SELV type.
6.1

STO Channel Operation

STO Function Active = No force/torque production is possible in motor
STO Function Inactive = Force/torque production in motor is under control of the drive
Table 5
The table above shows the operation of the STO channels.
0 = Voltage applied to the STO input is less than or equal to the rated maximum de-energize level.
1 = Voltage applied to the STO input is greater than or equal to the rated minimum energize level.
A motion control system design for Cat. 3 PL d, and/or SIL 3 rating must use 2 channels for the STO function.
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STO STO STO Function State
IN1 IN2
0 0 STO function is active , both inputs de-energized
1 0
STO function is active, one input de-energized
0 1
1 1 STO function is inactive, both inputs energized
16-01553 Rev 00
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