Cleco mPro300GCD-STO Beschreibung Seite 18

1
EN
Pin Signal
1
NC
2
3 FB-1-Out
4 STO-A
5 GND_STO
STO-B
6
FB -2
7
8 GND_STO
9.3 Control signals STO-A and STO-B
With the two control inputs STO-A and STO-B, the STO
safety function is requested by two channels. They allow
the direct connection of safe semiconductor outputs (elec-
tronic safety relays, active safety sensors) and of switching
contacts (safety relays with relay outputs, passive safety
sensors, such as positively driven position switches),
see9.6 Assembly and installation, Page 19.
To request the STO safety function, the 24 V control volt-
age at both control inputs STO-A and STO-B is switched
off (0 V). If both control signals are switched off simultane-
ously or within a specified discrepancy time, then the STO
safety function is active.
Chapter 4 Technical Specifications,
Page 10 describes the technical specifica-
tions for the controller inputs in the speci-
fied operating range of logic voltages.
Tolerance ranges are defined for the input voltage range of
the control inputs STO-A and STO-B. The amount of
energy stored in the components of the STO circuit (e.g.,
capacitors) depends on the magnitude of the input voltage.
During switching operations, these amounts of energy
must be charged or discharged. As a result, the dependent
values for the switch-off time for the transition to the safe
state (STO) come about from the input voltage.
The requirements for the time response result from the
technical specifications in Chapter 4 Technical Specifica-
tions, Page 10. The time response itself is described in
Chapter9.5 Time response, Page 19.
Discrepancy time
The transition between a safe and an unsafe state is initi-
ated by level changes at the control inputs STO-A and
STO-B. According to the specifications for the safety func-
tion, both levels must be identical; otherwise an error mes-
sage will be generated. A state machine in the controller
monitors both signals over time. Due to component toler-
ances or bouncing contacts, the level changes never occur
at exactly the same time. This is tolerated by the so-called
18
Description
Potential-free Feedback Contact 1
Output for control signal A for con-
trolling the STO safety function of the
next controller, bridged with X41.4
Reference potential for all voltages at
X42
Output for control signal B for con-
trolling the STO safety function of the
next controller, bridged with X41.6
Potential-free Feedback Contact 2,
bridged with X41.7
Reference potential for all voltages at
X42
discrepancy time as long as the level changes occur within
this time. If the levels of the control signals STO-A and
STO-B are different for longer than this time, a transition is
made to an error state that can not be reset. The discrep-
ancy time Δt is 100 ms. This can not be parameterized.
The signals STO-A and STO-B should be
switched simultaneously if possible.
Test pulses
Test pulses from safety controllers are not tolerated and
must be deactivated for system availability. The exclusive
use of Cleco Production Tools accessories allows the short
circuit fault exclusion.
Feedback contact FB
The feedback contact indicates the safe state. If the STO
safety function is not active, then the feedback contact is
open. This is also the case, for example, when the 24 V
logic supply voltage is switched off due to a defect or a fail-
ure of the supply voltage. When the STO safety function is
active, the relay contact is closed.
Note
The feedback contact has a single-chan-
nel design and may be used for diagnos-
tic purposes, but not in the safety circuit.
The following table shows the state of the feedback con-
tact, depending on the input signals and the time. A pre-
condition is always the error-free state (Row 1 or 4). The
time Δt is the discrepancy time 100 ms.
Row STO-A
1 0
2 0
3 1
4 1
The technical specifications for the feedback contact are
given in Chapter 4 Technical Specifications, Page 10.
P2552HW | 2021-04
When switching on, the feedback contact
may briefly deviate from the input signals
until the nutrunner control is ready for op-
eration.
STO-B FB
closed
0 1
1 0 0 → Δt → 1
0 Δ 0 → Δt → 1
0 → t → 1
1 0
Apex Tool Group
Leads to
diagnostic
error
after Δt
0
0