pizzato FOG124 Manual Del Usuario página 7

Activation areas for SM D•T, SM L•T, SM G•T actuators
(mm) 25
20
15
10
5
-20 -15 -10 -5 0 5 10 15
0
Activation areas for SM E•T actuators
(mm) 30
25
20
15
10
5
-20 -15 -10 -5 0 5 10 15
0
Legend:
Rated operating distance s (mm)
n
Rated release distance s (mm)
nr
Note: The progress of the activation areas is for reference only; the possible applica-
tion on ferromagnetic surfaces can reduce the operating distances.
5 OPERATION
5.1 Definitions
States of the sensor:
- OFF: sensor off, not powered.
- POWER ON: state immediately following switch on, during which the sensor carries out
internal tests.
- RUN: state in which the sensor is in normal operation.
- ERROR: safety state in which the outputs are disabled. Indicates presence of a
failure, either internal or external to the device, such as for example:
- a short circuit between the safety outputs (OS1, OS2)
- a short circuit between a safety output and ground, or
- a short circuit between a safety output and the supply voltage
To exit this state, the sensor must be restarted.
- The EDM External Device Monitoring function (where present) is a function which
allows the device to monitor the state of external contactors. Activation and deac-
tivation of external contactors must follow the ST sensor safety outputs within a
predefined time period (see paragraph TECHNICAL DATA).
5.2 General operation description
ACT
f2
f4
EDM
O3
IN
OUT
f1
f3
IS1 OS1
IS2 OS2
f0
PWR
A1 A2
- in versions without safety inputs IS1 and IS2, presence of the actuator is sufficient;
- in versions with safety inputs IS1 and IS2, presence of the actuator and activation of
inputs IS1, IS2 are checked;
- in versions with EDM, presence of the actuator, activation of inputs IS1, IS2, and
presence of the feedback signal of the contactors are checked.
In the RUN state, function f0 carries out internal test cycles in order to identify any
failures. Detection of any internal error switches the sensor to the "ERROR" state
(PWR LED continuously red) which deactivates immediately the safety outputs. The
"ERROR" state can be reached also where short-circuits between the safety outputs
(OS1, OS2), or a short circuit of an output towards ground or towards the supply volt-
age, are identified. In this case also, the F3 function deactivates the safety outputs
and the error state is indicated by the OUT LED flashing red.
The O3 signalling output, depending on the version selected, activates or deactivates
during the "RUN" state corresponding to detection of the actuator within the activation
area, independently of the state of any IS1 and IS2 inputs. The state of output O3 is
displayed via the ACT LED.
5.3 Description of operation in versions with safety inputs IS1 and IS2 (articles
ST D•31•••, ST D•42•••, ST D•51•••, ST D•71•••, ST D•82•••)
The f1 function evaluates the state of inputs IS1, IS2.
The IS1 and IS2 inputs are monitored not only for their state, but also for their coher-
ence: generally the inputs are actuated simultaneously. In the event of deactivation
of just one of the two inputs, the sensor deactivates the safety outputs and signals
a non-coherent condition of the inputs via the IN LED flashing green/orange. Both
inputs must be deactivated, for subsequent reactivation, so that the safety outputs can
be reactivated.5.4 Description of operation in versions with EDM input (articles
ST D•51•••)
The f4 function carries out a check of the NC contacts of contactors or forcibly guided
relays controlled by the safety outputs of the sensor itself; this check is carried out by
(mm) 25
20
15
10
5
20 -
20 -15 -10 -5 0 5 10
0
(mm)
(mm) 30
25
20
15
10
5
20 -20 -15 -10 -5 0 5 10
0
Following correct installation in accordance
with these instructions, the sensor can be
powered. The diagram shows the logic
functions which interact inside the sensor.
In the initial "POWER ON" state, the sensor
f0 function carries out an internal self diag-
nosis. When this terminates successfully,
the device switches to the "RUN" state. If
the test is not passed, the sensor enters the
"ERROR" state.
The "RUN" state is the normal operation
state: the f2 function checks the presence
of the actuator within the safety activation
area.
The f3 function enables safety outputs OS1
and OS2 according to the sensor version:
the sensor monitoring the EDM (External Device Monitoring) input. When the safety
inputs are active and the actuator is in the activation zone, the safety outputs are
activated only when the EDM input is active. When the safety outputs are activated,
the device checks that the EDM input deactivates within the time t
outputs are deactivated, the device checks that the EDM signal reactivates within the
time t .
EDM
If the maximum time t
EDM
ing the safety outputs (if they are enabled) and indicating the error via the IN LED
flashing red.
15 20
(mm)
5.5 Connection in series with safety modules
Where a sensor with no EDM input is used, the OS1 and OS2 safety outputs must be
connected to a safety module or to a safety PLC.
The device also has an O3 signalling output that is activated (in articles ST D•2••••,
ST D•3••••, ST D•4••••) or deactivated (in articles ST D•6••••, ST D•7••••, ST D•8••••)
when the corresponding guard is closed. Depending on the specific requirements
of the implemented system, this information can be managed by a PLC, or a
programmable Pizzato Elettrica CS MP series safety module. This enables control of
both safety and signalling outputs.
Connection example
with safety module and PLC
15 20
(mm)
IS1
ST D••••••
OS1
IS1
ST D••••••
OS1
IS1
ST D••••••
OS1
Ixx
Pizzato Elettrica
CS series
safety module
It is possible to install multiple cascade-connected sensors, up to a maximum of 32
units, whilst maintaining safety category 4 / PL e according to EN ISO 13849-1 and
integrity level SIL CL 3 according to EN 62061.
Check that the PFH and MTTFd values of the system consisting of the cascade of de-
vices and the entire safety circuit meet the requirements of the SIL/PL level requested
by the application.
For this connection type, the following warnings must be observed.
- Connect the inputs of the first device in the chain to the supply voltage.
- The OS1 and OS2 safety outputs of the last device in the chain must be connected
to the safety circuit of the machine.
- Where a safety module is used, check that the properties of safety outputs OS1/
OS2 are compatible with the safety module inputs (see paragraph INTERFACING).
- Respect the stray capacitance limits on the output lines indicated in the electrical
data (see paragraph TECHNICAL DATA).
- Check that the response time of the cascade meets the requirements of the safety
function to be implemented.
- The activation time of the cascade must be calculated taking into account the re-
sponse time of every single device.
The maximum number of 32 cascade-connected devices also depends on the
lengths and cross-sections of the wires used between the devices. Our technical
support service can help you with calculating the maximum distances and minimum
cross-sections of the wires to be used, for correct operation of cascade-connected
devices (see paragraph SUPPORT).
5.6 EDM connection (External Device Monitoring)
IS1
ST D•310••
OS1
IS1
ST D•310••
OS1
IS1
ST D•51•••
OS1
K1
7/30
is exceeded, the system goes into ERROR state, deactivat-
Connection example
with programmable safety module
+ Vcc
IS2
O3
OS2
IS2
O3
OS2
IS2
O3
OS2
Ixx
PLC
For certain specific applications, as an alter-
+
native to connection to safety modules, it is
IS2
possible to use the ST D•51••• article with
O3
check of the NC contacts of the forcibly guid-
OS2
ed relays (K1, K2) connected to the EDM
input, installed as the last sensor in the cas-
IS2
cade.
O3
OS2
IS2
O3
EDM
OS2
K2
. When the safety
EDM
+ Vcc
IS1 IS2
ST D•••••• O3
OS1 OS2
IS1 IS2
ST D••••••
O3
OS1 OS2
IS1 IS2
ST D••••••
O3
OS1 OS2
Ixx Ixx
Pizzato Elettrica
CS MP series
programmable safety module