Festo CMMS-ST-C8-7-G2 User manual

Description
STO safety function
(SafeTorqueOff)
8040102
1404NH
[8034464]
Motor controller
CMMS-ST-C8-7-G2

CMMS-ST-C8-7-G2
2 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH –
Translation of the original instructions
GDCP-CMMS-ST-G2-S1-EN
Pilz
®
and PNOZ
®
are registered trademarks of the respective trademark owners in certain countries.
Identification of hazards and instructions on how to prevent them:
Warning
Hazards that can cause death or serious injuries.
Caution
Hazards that can cause minor injuries or serious material damage.
Other symbols:
Note
Material damage or loss of function.
Recommendations, tips, references to other documentation.
Essential or useful accessories.
Information on environmentally sound usage.
Text designations:
• Activities that may be carried out in any order.
1. Activities that should be carried out in the order stated.
– General lists.

CMMS-ST-C8-7-G2
Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English 3
Table of Contents – CMMS-ST-C8-7-G2
1 Safety and requirements for product use 7......................................
1.1 Safety 7..................................................................
1.1.1 General safety instructions 7.........................................
1.1.2 Intended use 7.....................................................
1.1.3 Foreseeable misuse 8...............................................
1.1.4 Achievable safety level, safety function in accordance with EN ISO 13849-1 8...
1.2 Requirements for product use 9...............................................
1.2.1 Technical prerequisites 9............................................
1.2.2 Qualification of the specialized personnel (requirements for the personnel) 9...
1.2.3 Diagnostic coverage (DC) 9...........................................
1.2.4 Range of application and certifications 10................................
2 Description of the safety function STO 11........................................
2.1 Product overview 11.........................................................
2.1.1 Purpose 11........................................................
2.1.2 Interfaces 11.......................................................
2.2 Function and application 12....................................................
2.2.1 Description of the safety function STO 13................................
2.2.2 Overview of interfaces [X1] and [X3] 15..................................
2.2.3 Runtime performance 16..............................................
2.3 Switching example STO – “Safe Torque Off” 17....................................
2.3.1 Explanations of the switching example 17................................
2.3.2 STO request 18.....................................................
2.3.3 Restart after termination of the STO status 19.............................
2.3.4 STO timing diagram 20...............................................
2.4 Switching example SS1 – “Safe Stop 1” 21.......................................
2.4.1 Explanations of the switching example 21................................
2.4.2 Request SS1 23.....................................................
2.4.3 Restart after termination of the SS1 function and STO status 24..............
2.4.4 Timing diagram SS1 25...............................................
2.4.5 Parameterisation example 26..........................................
2.5 Testing the safety function 27..................................................
3 Mounting and installation 28..................................................
3.1 Mounting / dismantling 28.....................................................
3.2 Electrical installation 28.......................................................
3.2.1 Safety instructions 28................................................
3.2.2 Ports [X1] and [X3] 29................................................

CMMS-ST-C8-7-G2
4 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English
4 Commissioning 30...........................................................
4.1 Prior to commissioning 30.....................................................
4.2 Performance test, validation 31.................................................
5Operation 33...............................................................
5.1 Obligations of the operator 33.................................................
5.2 Maintenance and care 33......................................................
5.3 Diagnostics and fault clearance 33..............................................
5.3.1 Status indicators 33.................................................
5.3.2 Error messages 33...................................................
6 Modification and replacement of the motor controller 35............................
6.1 Repair or replacement of the integrated protection circuit 35.........................
6.2 De-commissioning and waste management 35.....................................
A Technical appendix 36........................................................
A.1 Technical data 36............................................................
A.1.1 Safety engineering 36................................................
A.1.2 General, operating and environmental conditions CMMS-ST-...-G2 37..........
A.1.3 Electrical data [X1], [X3] 38............................................
B Glossary 40................................................................

CMMS-ST-C8-7-G2
Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English 5
Notes on this documentation
This documentation serves the purpose of safe work with the safety function STO – “Safe Torque Off ”
with use of the motor controller CMMS-ST-...-G2.
• Always observe in addition the general safety regulations for the CMMS-ST-...-G2.
The general safety regulations for the CMMS-ST-...-G2 can be found in the description
Mounting and Installation , GDCP-CMMS-ST-G2-HW-... (Tab. 2).
Observe the information regarding safety and the requirements for product use in chapter 1.
Product identification
This documentation refers to the following versions:
– Motor controller CMMS-ST-...-G2 Rev 05 and higher.
– Firmware FW 1.4.0.1.4 and higher.
The illustration on the rating plate can be found in the description Mounting and Installation,
GDCP-CMMS-ST-G2-HW-...
Service
Please consult your regional Festo contact if you have any technical problems.
Issue status of the specified standards
Standard: issue status
EN 60204-1:2006/A1:2009-02 EN 61800-5-1:2007-09 EN ISO 12100:2010-11
EN 61800-2:1998-04 EN 61800-5-2:2007-10 EN ISO 13849-1:2008-06
Tab. 1 Issue statuses

CMMS-ST-C8-7-G2
6 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English
Documentation
Additional information on the motor controllers can be found in the following documentation:
Documentation Type of
equipment
Contents
Mounting and
installation
GDCP-CMMS-AS-G2-HW-... CMMS-AS –Mounting
Itllti
(i
ll ti )
GDCP-CMMD-AS-HW-... CMMD-AS
–
Installation (
p
in allocation)
– Error messages
– Technical data
GDCP-CMMS-ST-G2-HW-... CMMS-ST
Functions and
commissioning
GDCP-CMMS/D-FW-... CMMS-AS
CMMD-AS
CMMS-ST
– Control interfaces
– Operating modes/operational func-
tions
– Commissioning with FCT
– Error messages
STO safety
function
GDCP-CMMS-AS-G2-S1-... CMMS-AS – Functional safety engineering with
GDCP-CMMD-AS-S1-... CMMD-AS
y
gg
the safety function STO (safe torque
off)
GDCP-CMMS-ST-G2-S1-... CMMS-ST
Device profile
FHPP
GDCP-CMMS/D-C-HP-... CMMS-AS
CMMD-AS
CMMS-ST
– Description of the interfaces:
– CAN bus (CANopen)
–InterfaceCAMC-PB(PROFIBUS)
– Interface CAMC-DN (DeviceNet)
– Control and parameterisation via
the device profile FHPP (Festo
profile for handling and positioning)
with PROFIBUS, DeviceNet or
CANopen.
Device profile
CiA 402,
GDCP-CMMS/D-C-CO-... CMMS-AS
CMMD-AS
CMMS-ST
– Description of the interface:
– CAN bus (CANopen, DriveBus)
– Control and parameterisation via
device profile CiA 402 (DS 402).
Software Help Help on the CMMS-AS plug-in CMMS-AS – Surface and functions in the Festo
Help on the CMMD-AS plug-in CMMD-AS Configuration Tool for the plug-in
Help for the CMMS-ST plug-in CMMS-ST
Tab. 2 Documentation on the motor controllers
The documentation is available on the following media:
– CD-ROM (scope of delivery)
– Support portal: www.festo.com/sp

1 Safety and requirements for product use
Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English 7
1 Safety and requirements for product use
1.1 Safety
1.1.1 General safety instructions
• Always observe in addition the general safety regulations for the CMMS-ST-...-G2.
The general safety regulations for the CMMS-ST-...-G2 can be found in the description
Mounting and Installation, GDCP-CMMS-ST-G2-HW-... (Tab. 2, page 6).
Note
Loss of the safety function.
The safety functions might fail if you do not comply with the parameters required for the
surroundings and connections.
• In particular, you must provide input voltages which are within the tolerances spe-
cified in Technical data, appendix A.1.
Note
Damage to the motor controller due to incorrect handling.
• Switch off the supply voltage before mounting and installation work. Switch on
supply voltage only when mounting and installation work are completely finished.
• Observe the specifications for handling electrostatically-sensitive devices.
1.1.2 Intended use
The CMMS-ST-...-G2 motor controller supports the following safety function:
– “Safe Torque Off” (STO) up to category 3 / PL d in accordance with EN ISO 13849-1.
The motor controller CMMS-ST-...-G2 is a product with safety-relevant functions and is intended for
installation in machines or automation systems. Use it only:
– in excellent technical condition,
– in its original state without unauthorised modifications,
– within the product's limits, as defined by the technical data Appendix A.1,
– within the specified service life of the switching elements Appendix A.1, Tab. A.6,
– in an industrial environment.

1 Safety and requirements for product use
8 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English
Note
In the event of damage caused by unauthorised manipulation or improper use, the
guarantee is invalidated and the manufacturer is not liable for damages.
1.1.3 Foreseeable misuse
The following foreseeable misuses are among those not approved as intended use:
– use outdoors,
– use in non-industrial areas (residential areas),
– use in applications where switching off can result in hazardous movements or conditions.
Note
– The STO function may not be used as the sole safety function for drives subject to
permanent torque or force (e.g. suspended loads).
– Bypassing of safety equipment is not allowed.
– Repairs to the motor controller are not allowed!
The STO (Safe Torque Off) function does not provide protection fromelectric shock, but
only against hazardous movements (Description, mounting and installation,
GDCP-CMMS-ST-G2-HW-...)!
In applications with extremely high requirement rates, the service life of the switching elements must
be taken into account in the design (replacement interval for the motor controller, Appendix A.1,
Tab. A.1 and Tab. A.6) .
1.1.4 Achievable safety level, safety function in accordance with EN ISO 13849-1
The motor controller CMMS-ST-...-G2 with integrated STO safety function fulfils the requirements of the
test regulations for
– Category 3 / PL e in accordance with EN ISO 13849-1
and can be used in applications up to Cat. 3 / PL d in accordance with EN ISO 13849-1.
The achievable safety level depends on the other components used to implement the safety function.

1 Safety and requirements for product use
Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English 9
1.2 Requirements for product use
• Make this documentation available to the design engineer, installer and personnel responsible for
commissioning the machine or system in which this product is used.
• Make sure that the specifications of the documentation are always complied with. When so doing,
also take into account the documentation for the other components (e.g. motors, cables, etc.).
• Take into consideration the legal regulations applicable for the destination, as well as:
– regulations and standards,
– regulations of the testing organizations and insurers,
– national specifications.
• If the safety function is demanded, protection against automatic restart corresponding to the re-
quired category must be furnished. Among other means, this can take place through an external
safety switching device.
1.2.1 Technical prerequisites
General conditions for the correct and safe use of the product, which must be observed at all times:
• Comply with the connection and environmental conditions of the motor controller (Appendix A.1)
and all connected components specified in the technical data.
Only compliance with the limit values or load limits will enable operation of the product in compli-
ance with the relevant safety regulations.
• Observe the instructions and warnings in this documentation.
1.2.2 Qualification of the specialized personnel (requirements for the personnel)
The device may only be set into operation by a qualified electrotechnician who is familiar with:
– the installation and operation of electrical control systems,
– the applicable regulations for operating safety-engineered systems,
– the applicable regulations for accident protection and occupational safety, and
– the documentation for the product.
1.2.3 Diagnostic coverage (DC)
Diagnostic coverage depends on the connection between the motor controller and the control loop
system as well as the implemented diagnostic measures Section 5.3.
If a potentially dangerous malfunction is recognised during the diagnostics, appropriate measures
must be taken to maintain the safety level.
Note
Check whether a fault exclusion of cross circuits in the input circuit and connection
wiring is possible in your application.
If not: If applicable, use a safety switching device with cross-circuit detection for control
of the safety function as well as an appropriate filter construction group for filtering the
test pulses at the control ports of the CMMS-ST-...-G2.

1 Safety and requirements for product use
10 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English
1.2.4 Range of application and certifications
The motor controller with integrated STO safety function is a safety-related part of the control systems.
The motor controller carries the CE marking.
Standards and test values which the product must comply with and fulfils can be found in the section
“Technical data” Appendix A.1. The product-relevant EU directives can be found in the declaration of
conformity.
Certificates and declaration of conformity on this product can be found at
www.festo.com/sp.

2 Description of the safety function STO
Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English 11
2 Description of the safety function STO
2.1 Product overview
2.1.1 Purpose
As processes become increasingly automated, protecting people from potentially hazardous move-
ments is gaining in importance. Functional safety describes required measures by electrical or electron-
ic equipment to reduce or eliminate malfunction-induced dangers. In normal operation, protective
devices prevent human access to hazardous areas. In certain operating modes, during set-up, for ex-
ample, people need to be in hazardous areas. In such situations, the machine operator must be protec-
ted by drive and internal control measures.
The functional safety engineering integrated in the motor controller meets the requirements of the
controller and drive for optimised implementation of protective functions. Planning and installation
complexity is reduced. The use of integrated functional safety engineering increases machine function-
ality and availability over the levels achieved by conventional safety technology.
2.1.2 Interfaces
The motor controller CMMS-ST-...-G2 has 2 interfaces for control of the STO safety function.
2
3
14
1Top side of housing
2I/O interface [X1]
3Bottom side of housing
4STO interface [X3]
Fig. 2.1 Motor controller CMMS-ST-...-G2

2 Description of the safety function STO
12 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English
2.2 Function and application
The CMMS-ST-...-G2 motor controller has the following safetyfeatures:
– “Safe Torque Off” function (STO),
– potential-free acknowledgement contact for the operating status,
The function “Safe Stop 1” (SS1) can be achieved with a suitable external safety switching device and
appropriate circuitry of the motor controller CMMS-AS-...-G2.
Safety function Requirements of the safety switching
device
1)
Switch-off behaviour Stop
category
STO Safe
Torque Off
– 2 safety contacts, non-delayed
– Connection option for safety com-
mand devices, e.g. emergency stop
switch, protective door switch, light
curtains, etc.
0
SS1 Safe Stop 1 – 1 safety contact non-delayed
– 2 safety contacts relapse delayed
– Connection option for safety com-
mand devices, e.g. emergency stop
switch, protective door switch, light
curtains, etc.
1
1) Or comparable safety switching device with corresponding safety contacts
Tab. 2.1 Selection of the safety function

2 Description of the safety function STO
Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English 13
2.2.1 Description of the safety function STO
Use the “Safe Torque Off ” function (STO) whenever you have to reliably disconnect the energy supply
to the motor in your application.
The safe torque off function switches off the following Fig. 2.2.:
– driver supply for the power semiconductor.
– activation of the power semiconductor (PWM).
Note
The STO function request must always run in two channels over X3.2 and X1.21
(end stage enable).
2nd switch-off
path
Activation of driver supply relay
(switch-off of the driver supply)
High = driver supply on
Low = “pulse blocker” active
Driver sup-
ply monit-
oring
Potential-free driver
supply acknowledg-
ment contact
12 V - MOSFET
driver supply
(+12 V_TR)
+12 V_TR_switched
1st switch-off path
Output stage driver
MOSFET output
stage
Switch-off of the
PWM control signals
over DIN4
Output stage enable DIN4
Controller enable DIN5
84
2
1,2,3,4
48
µC
Fig. 2.2 “Safe torque off ” - functional principle for CMMS-ST-...-G2
With the Safe Torque Off function (STO), the energy supply to the motor is reliably interrupted by
switching off the end stage enable and supply to the final output stage. The drive cannot generate
torque or any force and so cannot make any dangerous movements.

2 Description of the safety function STO
14 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English
With suspended loads or other external forces, additional measures must be taken to ensure that the
load does not drop (e.g. mechanical holding brakes). In the STO “Safe Torque Off” status, the idle posi-
tion is not monitored.
The machine must be stopped in a safe manner, e.g. via a safety switching device.
If the STO function is activated with a moving drive, the motor starts to coast uncontrolled after max.
5 ms. After that, the automatic brake control is activated.
Note
If uncontrolled coasting can result in a hazard or damage, additional measures are
required.
Note
A clamping unit is actuated by the non-safety-relevant firmware of the motor controller
CMMS-ST-...-G2.
If you use motors with a holding brake, the holding brake is worn each time the STO is switched off
while the motor is running.
Therefore, when using the “STO” function, do not use motors with holding brakes; use clamping units
that permit emergency braking or use automatic locking axis mechanisms.
The holding brakes used by Festo motors are not suitable for active deceleration - only for
holding a position!
Application examples for the STO function are manual manipulations during set-up, equipping and fault
clearance. Use of the integrated solution offers several advantages:
– fewer external components, e.g. contactors.
– less wiring effort and space requirements in the control cabinet.
– and thus lower costs.
Another advantage is the availability of the system. The integrated solution allows the intermediate
circuit of the controller to remain charged. This means no significant waiting time when the system is
restarted.
Note
There is a danger that the drive will advance if there are multiple errors in the
CMMS-ST-...-G2.
Failure of the motor controller output phase during the STO status (simultaneous short
circuit of 2 power semiconductors in different phases) may result in a limited detent
movement of the rotor. The rotation angle / path corresponds to a pole pitch. Example:
Rotating axis, stepper motor, 50 pin pairs Movement <3.6° at the motor shaft.

2 Description of the safety function STO
Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English 15
2.2.2 Overview of interfaces [X1] and [X3]
The motor controller has control ports for requesting the safety function at the following interfaces
Section 3.2:
– 25-pin connection [X1] on the top side with the control port (1st switch-off path) and the controller
enable control port (for implementation of the SS1 function in combination with an externally safe
time relay).
– 6-pin connection [X3] on the bottom with a control port (2nd switch-off path), an acknowledgment
contact and a 24 V auxiliary supply for external sensors.
A safety circuit for additional interfaces on the CMMS-ST-...-G2 motor controller is neither required nor
intended.
Tab. A.6 in appendix A.1.3 describes the technical data for the control ports.
Cross-circuit detection in the input circuit is not carried out by the motor controller.
The inputs have no tolerance against test pulses (OSSD).
Interface Port Description
Pin Designation
[X1] 6GND24 Reference potential for digital inputs and outputs
9DIN5 Controller enable (high active)
18 +24 V 24 V supply provided
21 DIN4 Output stage enable (high active)
[X3] 124 V Auxiliary power supply (24 V DC logic supply of the motor control-
ler provided).
2Rel Activation of driver supply relay
High = driver supply switched on
Low = “pulse blocker” active, driver supply switched off
30V Reference potential for digital inputs and outputs.
51(NC1)Acknowledgment contact for the status “Safe Torque Off” (STO)
– Acknowledgment contact closed = “Safe Torque Off” (STO)
active (or controller switched off)
62(NC2)
Tab. 2.2 Function of the connections
For STO in category 3‚ PL d in accordance with EN ISO 13849-1, two channels are required, that is, an
unintended restart must be reliably prevented through two separate paths that are completely inde-
pendent of each other. These two paths for interrupting the energy supply to the drive with the reliable
impulse block are called switch-off paths:
1st switch-off path:
Output stage enable via [X1] (blocking of the PWM signals; the MOSFET drivers are no longer actuated
with pulse patterns).
2nd switch-off path:
Interruption of the supply for the eight drivers for the end stage MOSFETs via [X3] using a relay (the
MOSFET drivers are separated from the power supply via a relay, thus preventing the PWM signals from
reaching the MOSFETs).

2 Description of the safety function STO
16 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English
A plausibility check is performed in the µP between the relay control for the output stage driver supply and
the monitoring of the driver supply. This serves to provide both error detection of the impulse block and
suppression of the error message E 05-2 (“driver supply undervoltage”) occurring in normal operation.
Potential-free acknowledgment contact:
Further, the integrated circuit for “Safe Torque Off” has a potential-free acknowledgment contact ([X3]
pin 5 and 6) for the presence of the driver supply. This is an N/C contact. It must be connected to an
external safety controller or the higher-order controller, for example. Through this controller, the STO
function must be checked regularly (e.g. every 24 hours or at the beginning of the shift, if possible at
every STO request).
If an error occurs in the plausibility check, the control system must prevent further operation, for example, by
switching off the intermediate circuit voltage or breaking off the output stage enable by the PLC.
The feedback contact has a single channel and may only be used for monitoring.
Tab. A.7 in Appendix A.1.3 describes the electrical data and runtime performance of the
acknowledgment contact.
When the 24 V supply to the basic device is turned on and off, the switching status of the relay
may - due to the internal supply voltages powering up at a different speed - deviate briefly
(approx. 100 ms) from the status of the controller for the driver supply relay Rel [X3.2].
Registration of the status of the acknowledgment contact NC1/NC2 is required at every
request of the safety function.
When the safety function has been requested, a change in signal must occur at the ac-
knowledgment contact within an application-specific time. A safety-related reaction must
be initiated in the event of a violation.
Auxiliary supply 24 V, 0 V [X1] and [X3]
The motor controller CMMS-ST-...-G2 makes available one 24 V auxiliary supply each at [X1] and [X3].
This can be employed when using the acknowledgment contact NC1/NC2 or to supply external, active
sensors.
Tab. A.8 in appendix A.1.3 describes the electrical data for the auxiliary supply.
2.2.3 Runtime performance
The runtime performance for typical applications can be found in the sample circuits:
– Sample circuit for STO in Section 2.3.
– Sample circuit for SS1 Section 2.4.

2 Description of the safety function STO
Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English 17
2.3 Switching example STO – “Safe Torque Off”
12
3
T1
Pilz PNOZ s3
A1
S11 S12 S21 S22 S34 Y32
S1
22
21
A2
11
12
S2
T2
Festo CMMS-ST-...-G2
24V
0V
-X9
T1
219
DIN4 DIN5 -X1
2 3
REL
0V
NC2 NC1
-X3
13
14
23
24
T1
FE
Input T3 Acknowledgment T1
13
14
24 V DC
0VDC
Only relevant connections drawn
Output T3 Controller enable Output T3 Output stage enable
56
4
ZK+
48 V DC
1Motor controller with safety function
(T2, only relevant connections represented)
2Safety switching device (T1)
3Emergency stop switches
4Inputs and outputs of the higher-order
controller (T3, 24 V)
Fig. 2.3 Circuit diagram, safety function STO
2.3.1 Explanations of the switching example
The switching example shows a combination of the CMMS-ST-...-G2 with a PNOZ s3 safety switching
device from Pilz. A circuit is shown with an emergency stop switch that carries out the safety function
“Safe torque switch-off (STO)”. The emergency stop switch (S1) can be replaced by another safety
command device, e.g. safety door switch.
You can find technical data, such as max. current, etc., in the data sheet of the safety switching device
used.
Due to the drawn circuitry, a two-channel operation with cross-circuit detection is possible. This per-
mits detection of:
– earth faults in the start and input circuit.
– short circuits in the input circuit / start circuit.
– cross circuits in the input circuit.
The removal of output stage enable via DIN4 [X1.21] as well as switching off of the driver supply via Rel
[X3.2] results in the motor coasting to a stop.

2 Description of the safety function STO
18 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English
Note
If external forces (e.g. suspended loads) affect the drive, additional measures (e.g.
mechanical holding brakes) are necessary to avoid hazards.
Note
The stop function SS1, “Safe Stop 1”, in which the drive is brought to rest, is funda-
mentally preferable.
The holding brake of the EMMS-ST-…Bis not appropriate for braking the motor. It only
serves for functional holding of the motor shaft. Additional measures are required for use
in safety-oriented applications.
2.3.2 STO request
The following steps describe the process when activating the STO status (Timing diagram section 2.3.4):
a) After actuation of the emergency stop switch (S1), the N/O contacts (13, 14 and 23, 24) of T1 open
immediately. As a result, control of the driver supply relay Rel [X3.2] and output stage enable DIN4
[X1.21] are switched off simultaneously – “Safe Torque Off ” is activated.
b) With removal of the control signal for the relay to switch off the driver supply, the capacitors are
discharged in this voltage branch. After no more than 5 ms (t1), the output stage is no longer active.
The motor coasts to a stop.
c) A maximum of 2.5 ms (t2) later, the output for control of the holding brake is switched off.
d) Not later than 12 ms (t
STO
) after removal of the control of the driver supply relay and output stage
enable, the output stage is reliably switched off and the STO status is active.
e) For mechanical reasons, the holding brake requires some time until it is closed - typically after ap-
prox. 50 ... 500 ms (t3).
f ) Not later than 30 ms (t4) after removal of control of the driver supply Rel [X3.2], the acknowledg-
ment contact NC1/NC2, [X3.5/6] is closed.
g) Not later than 720 ms (t5) after 2-channel calling (DIN4 [X1.21] and Rel [X3.2] ), “H” is displayed on
the 7-segments display of the motor controller.

2 Description of the safety function STO
Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English 19
2.3.3 Restart after termination of the STO status
Before switching it on again, make sure that all hazards have been eliminated and the system can be
safely placed in operation again. A manual acknowledgment must be made through the optional S2
pushbutton corresponding to the risk evaluation for the application (see switching example).
To switch the output stage of the motor controller active again and thus operate the connected motor,
the following steps must be taken (Timing diagram section 2.3.4):
1. First, the control of the relay for switching the supply voltage of the output stage driver (2nd switch-
off path) must be switched through 24 V at Rel [X3.2] (related to 0 V [X3.3]).
a) This switches on the internal driver supply. The driver supply is recharged after no more than 20 ms (t6).
b) The potential-free acknowledgment contact NC1/NC2 [X3.5/6] is opened no later than 30 ms (t4)
after Rel [X3.2] is switched.
2. The switching time for the output stage enable DIN4 [X1.21] is freely selectable (t7). The release
should take place simultaneously with activation of the 2nd switch-off path via Rel [X3.2], but must
be present at least 2.5 ms (t8) before the rising edge of the controller enable DIN5 [X1.9].
c) With the rising edge of the controller enable, after a time delay ≤5 ms (t9), release of the motor
holding brake is triggered (if present) and the internal output stage enable takes place. For control
via the fieldbus, controller enable via fieldbus is also required beforehand. With FCT, a switch-on
delay can be set for the brake (t10), which causes the drive to be regulated to speed “0” for the
specified time, and only after this time has elapsed does it run to the set speed.
d) No later than 720 ms (t5) after ending of the 2-channel request, the “H” on the 7-segments display
goes out.

2 Description of the safety function STO
20 Festo – GDCP-CMMS-ST-G2-S1-EN – 1404NH – English
2.3.4 STO timing diagram
Controller enable
DIN5 [X1.9]
Output stage
enable DIN4
[X1.21]
Actual speed
value
Output stage
active
Open holding
brake BR+ [X6.2]
Holding brake
open (mechanical)
t1
7-segments
display
t3
t5
t2
Acknowledgment
contact NC1/NC2
[X3.5/6]
Driver supply relay
Rel [X3.2]
t4
Safe Torque Off
t5
‘H’
t4
t8
t7
t6
t10
t9
Open
Closed
Open
t
STO
t1 ≤5ms
t2 ≤2.5 ms
t
STO
≤12 ms
t3 L50 … 500 ms
(dependent on the brake used)
t4 ≤30 ms
t5 ≤720 ms
t6 ≤20 ms
t7 any
t8 >2.5 ms
t9 ≤5 ms (For control via the fieldbus, control-
ler enable via fieldbus is also required
beforehand)
t10 0 … 6553 ms (with FCT parameterised switch-
on delay brake)
Fig. 2.4 STO timing diagram