Festo CMMT-AS-S1 Series User manual

8075813
Servo drive
CMMT-AS-...-S1
8075813
2018-02
[8075815]
Description| Safety
function| STO, SBC,
SS1

Translation of the original instructions
ET 200SP®, PNOZ®, Pilz®, SIEMENS® are registered trademarks of the respective trademark owners in
certain countries.
2 Festo — CMMT-AS-...-S1 — 2018-02

3Festo — CMMT-AS-...-S1 — 2018-02
1 About this document................................................................................................... 5
1.1 Target group................................................................................................................. 5
1.2 Further applicable documents...................................................................................... 5
1.3 Product version............................................................................................................ 5
1.4 Product labelling.......................................................................................................... 5
1.5 Specified standards...................................................................................................... 5
2 Safety........................................................................................................................... 5
2.1 Safety instructions........................................................................................................ 5
2.2 Intended use................................................................................................................ 6
2.2.1 Application areas....................................................................................................6
2.2.2 Permissible components.........................................................................................6
2.3 Foreseeable misuse...................................................................................................... 6
2.4 Training of skilled personnel........................................................................................ 7
2.5 Approvals and certifications......................................................................................... 7
3 Service..........................................................................................................................7
4 Product overview......................................................................................................... 7
4.1 Safety functions............................................................................................................ 7
4.1.1 Function and application.........................................................................................7
4.1.2 Safety function STO................................................................................................ 7
4.1.3 Safety function SBC................................................................................................ 11
4.1.4 Safety function SS1................................................................................................ 15
4.1.5 Cross wiring of several servo drives........................................................................19
4.1.6 Error exclusion........................................................................................................20
4.1.7 Safety relay unit......................................................................................................20
4.1.8 Interfaces of the PDS.............................................................................................. 20
5 Installation.................................................................................................................. 21
5.1 Safety............................................................................................................................ 21
5.2 Installation STO............................................................................................................ 22
5.3 SBC installation............................................................................................................ 24
5.4 SS1 installation............................................................................................................ 25
5.5 Installation for operation without safety function......................................................... 26
6 Commissioning............................................................................................................ 26
6.1 Safety............................................................................................................................ 26
6.2 Check lists.................................................................................................................... 27
7 Operation..................................................................................................................... 29
8 Malfunctions............................................................................................................... 29
8.1 Diagnostics via LED...................................................................................................... 29
8.2 Repair............................................................................................................................30
9 Technical data............................................................................................................. 31
9.1 Technical data, safety equipment................................................................................. 31
Table of contents

9.2 Technical data product conformity and approvals......................................................... 35
9.3 General technical data...................................................................................................35
9.4 Technical data, electrical............................................................................................... 37
9.4.1 Motor auxiliary connection [X6B]........................................................................... 37
9.4.2 Inputs, outputs, ready contact at [X1A].................................................................. 38
9.4.3 Inputs and outputs to the axis [X1C]...................................................................... 42
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1 About this document
1.1 Target group
The document is targeted towards individuals who mount and operate the product. It is additionally
targeted towards individuals who are entrusted with the planning and application of the product in a
safety-oriented system.
1.2 Further applicable documents
This document describes the use of the safety functions Safe torque off (STO) and Safe brake control
(SBC) in accordance with EN61800-5-2.
It is possible to implement the safety function Safe stop 1 (SS1) with a suitable external safety relay
unit and appropriate circuitry of the servo drive.
• Observe safety instructions in the documentation ètextvar object does not exist.
All available documents for the product èwww.festo.com/pk.
1.3 Product version
This documentation refers to the following version of the device:
– Servo drive CMMT-AS-...-S1, revision R01 and higher, see product labelling
1.4 Product labelling
Product labelling ètextvar object does not exist.
1.5 Specified standards
Version
EN61131-2:2007 ENISO 13849-1:2015
IEC61800-5-1:2016 EN61508 Parts 1-7:2010
EN61800-3:2004+A1:2012 EN60204-1:2006+A1:2009+AC2010
EN61800-5-2:2017 EN62061:2005+AC:2010+A1:2013+A2:2015
EN 61800-2:2015 –
Tab. 1 Standards specified in the document
2 Safety
2.1 Safety instructions
The suitability for certain applications can only be determined in connection with the assessment of
further components of the subsystem.
Analyse and validate safety function of the entire system.
The safety functions are to be checked at adequate intervals for proper functioning. Selecting the type
of test and time intervals within the stated time period is the responsibility of the operator. The check
is to be conducted such that flawless functioning of the safety device can be verified in interaction
with all components. Time period for cyclical test è 9.1 Technical data, safety equipment.
Prior to initial commissioning, connect the control inputs of the safety functions STO and SBC. The
safety functions STO and SBC are available in the CMMT-AS as delivered without additional paramet-
erisation.
Keep the documentation throughout the entire product lifecycle.
About this document

2.2 Intended use
The CMMT-AS-...-S1 supports the following safety functions in accordance with EN61800-5-2:
– Safe torque off Safe torque off
– Safe brake control Safe brake control
– Safe stop 1 Safe stop 1, achievable with suitable safety relay unit and appropriate connection of
the servo drive
The safety function STO is intended to disconnect the torque of the connected motor, thereby prevent-
ing an unexpected restart of the motor.
The safety function SBC is intended to safely hold the motor and axle in their position at standstill.
The safety function SS1 is intended for rapid stop with subsequent torque switch off.
2.2.1 Application areas
Safety functions may only be used for applications for which the stated safety values are sufficient
è 9.1 Technical data, safety equipment.
2.2.2 Permissible components
The logic supply must meet the requirements of EN60204-1 (protective extra-low voltage, PELV).
If holding brakes and clamping units without certification are used, the suitability for the related
safety-oriented application must be determined through a risk assessment.
The motors must fulfil the requirements of EN61800-5-2 appendix D.3.5 and D.3.6 and of
EN60204-1. Motors approved or specified by Festo for the CMMT-AS fulfil the requirements.
The motor cables and brake lines must fulfil the requirements of EN61800-5-2 appendix D.3.1 and of
EN60204-1. Motor cables and brake lines approved by Festo for the CMMT-AS fulfil the requirements.
2.3 Foreseeable misuse
Foreseeable misuse, general
– Use outside the limits of the product defined in the technical data.
– Cross-wiring of the I/O signals of more than 10 servo drives CMMT-AS.
– Use in IT networks without insulation monitors for detection of earth faults.
When operated in IT networks, the potential relations change in case of error (earth fault of the
feeding mains supply) so that the rated voltage of 300V against PE, which is important for the
design of insulation and network disconnection, is exceeded. This error must be detected.
– Use of a diagnostic output for connection of a safety function.
The diagnostic outputs STA and SBA are not part of the safety circuit. The diagnostic outputs are
used to improve diagnostic coverage of the related safety function. The diagnostic outputs may
only be used in combination with the related safe control signals (AND link) and a reliable time
monitoring in the safety relay unit for switching additional safety-critical functions.
Foreseeable misuse of the safety function STO
– Use of the STO function without external measures for drive axles influenced by external torques.
If external torques influence the drive axle, the safetyfunction STO alone is not suitable to stop the
axle reliably. Additional measures are required to prevent dangerous movements of the drive axle,
such asuse of a mechanical brake in combination with the safety function SBC.
– Disconnection of the motor from the energy supply.
The safety function STO does not disconnect the drive from the power supply as defined by elec-
trical safety.
Safety
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Foreseeable misuse of the SBC function
– Use of an unsuitable holding brake or clamping unit, also in view of:
– Holding or brake torque and emergency brake characteristics, if required.
– Frequency of actuation
– Use of an unsuitable logic voltage supply
2.4 Training of skilled personnel
The product may be installed and placed in operation only by a qualified electro technician, who is
familiar with the topics:
– installation and operation of electrical control systems
– applicable regulations for operating safety-engineering systems
Work on safety-related systems may only be carried out by qualified personnel trained in safety engin-
eering.
2.5 Approvals and certifications
The product has the CE marking. Guidelines see
è 9.2 Technical data product conformity and approvals.
The product-relevant EC directives and standards are listed in the declaration of conformity
èwww.festo.com/sp.
The product is a safety device in accordance with the Machinery Directive. Safety-oriented standards
and test values that the product complies with and fulfils è 9.1 Technical data, safety equipment.
Observe that compliance with the named standards is limited to the CMMT-AS-...-S1.
3 Service
Contact your regional Festo contact person if you have technical questions èwww.festo.com.
4 Product overview
4.1 Safety functions
4.1.1 Function and application
The servo drive CMMT-AS-...-S1 has the following safety-related performance features:
– Safe torque off Safe torque off
– Safe brake control Safe brake control
– Safe stop 1 (SS1) with use of a suitable external safety relay unit and suitable wiring of the servo
drive
– Diagnostic outputs STA and SBA for feedback of the active safety function
4.1.2 Safety function STO
Fig. 1 Symbol STO
The function described here implements the safety function STO according to EN61800-5-2 (corres-
ponds to stop category 0 from EN60204-1).
Service
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The safety function STO is used when, in the application, the energy supply to the motor should be
safely switched off but there are no further requirements for a targeted standstill of the drive (such
asstop category 1 from EN60204-1 è 4.1.4 Safety function SS1).
Function and application STO
The safety function STO switches off the driver supply for the power semiconductor, thus preventing
the power end stage from supplying the energy required by the motor. The power supply to the drive
is safely disconnected when the safety function STO is active. The drive cannot generate torque and so
cannot make any hazardous movements. With suspended loads or other external forces, additional
measures must be taken to ensure that the load does not drop (e.g.mechanical clamping units). In
the STO status, the standstill position is not monitored.
The machines must be stopped and locked in a safe manner. This especially applies to vertical axles
without automatic locking mechanics, clamping units or counterbalancing.
NOTICE!
If there are multiple errors in the servo drive, there is a danger that the drive will move. Failure of the
servo drive output stage 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/travel
corresponds to a pole pitch. Examples:
•Rotating motor, synchronous machine, 8-pin è Movement <45° at the motor shaft
•Linear motor, pole pitch 20mm èMovement <20mm at the moving part
Functional principle STO
Fig. 2 Functional principle STO
Product overview
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1High-side output stage
2Low-side output stage
3Intermediate circuit voltage
Fig. 3 Output stage with power transistors
STO request
The STO safety function is requested over 2 channels by switching off the control voltage at both con-
trol ports #STO-A and #STO-B.
The drive behaves as follows when the STO safety function is requested:
– Behaviour of the drive with a running motor: The movement of the drive is not decelerated via a
braking ramp. The drive continues to move uncontrolled due to inertia or external forces until it
comes to a standstill by itself.
– Behaviour of the drive with a stopped motor: The drive is uncontrolled and can be moved through
external forces.
STO feedback through STA diagnostic contact
The status of the STO safety function can be reported to the safety relay unit through the STA dia-
gnostic output.
The STA diagnostic output displays whether the safe status has been reached for the STO safety func-
tions. The STA diagnostic output switches to high level only when STO is active in 2 channels through
the control inputs #STO-A and #STO-B.
#STO-A #STO-B STA
Low level Low level High level
Low level High level Low level
High level Low level Low level
High level High level Low level
Tab. 2 Level STA
If protective functions are triggered in both channels (STO-A and STO-B), e.g.with excessive voltage
at STO-A and STO-B, the internal protective functions switch off and STA likewise delivers high level.
Product overview
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Recommendation: The safety relay unit should check the status of the diagnostic output at each STO
request. The level of STA must change according to the logictable. The safety relay unit can cyclically
test the signals #STO-A and #STO-B, for high level with low testimpulses and for low level with high
testimpulses.
Timing STO
Fig. 4 STO timing diagram
Legend for STO timing
Term/abbreviation Explanation
#STO-A/#STO-B 2-channel input for STO request
#STO-HS/#STO-LS Internal triggering, PWM driver high side/low side
tSTO,TP Max. length, low test impulses1) at #STO-A/B
tSTO,In Max. delay until STO switches off (≤permissible reaction time when a safety
function is requested1))
Product overview
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Term/abbreviation Explanation
STA Feedback, STO active
tSTA,Out Max. delay for diagnostic feedback (≤permissible reaction time when a
safety function is requested1) + 10ms)
n Rotational speed
1) see Technical data, STO safety data
Tab. 3 Legend for STO timing
4.1.3 Safety function SBC
Fig. 5 Symbol SBC
The function described here implements the SBC safety function according to EN61800-5-2.
The SBC safety function is used for controlling a holding brake in the motor and a clamping unit or
brake on the axle to slow an axle down mechanically or stop it safely.
SBC function and application
The SBC safety function provides safe output signals for the control of brakes (holding brakes or
clamping units). Brakes are controlled over 2-channels by switching off the voltage at the following
outputs:
– Safe output BR+/BR– [X6B] for the holding brake of the motor
– Safe output BR-EXT/GND [X1C] for the external brake/ clamping unit
The holding brake and/or clamping unit engage and slow the motor or axle. Dangerous movements
should thus be braked mechanically. The braking time is dependent on how quickly the brake engages
and how high the energy level is in the system.
The use of only one brake is possible è Tab. 16 Safety reference data of the SBC safety functiononly
in case of low performance requirements. To do this, connect the brake either to BR+/BR– or to BR-
EXT.
NOTICE!
If there are suspended loads, they usually drop if SBC is requested simultaneously with STO. This can
be traced back to the mechanical inertia of the holding brake or clamping unit and is thus unavoid-
able. Check whether the SS1 safety function is better suited.
SBC may only be used for holding brakes or clamping units which engage in the de-energised state.
Ensure the lines are installed in a protected manner.
Functional principle SBC
Product overview
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Fig. 6 Functional principle SBC
SBC request
The SBC safety function is requested over 2 channels by switching off the control voltage at both con-
trol ports #SBC-A and #SBC-B:
– The #SBC-A request switches off the power to the signals BR+/BR-.
– The #SBC-B request switches off the power to the signal BR-EXT.
If there is a power failure in the logic voltage supply of the servo drive, power is also cut off to the
brake outputs.
After a request of SBC and subsequent cancellation, the safe brake control is only energised when the
functional microcontroller enables the holding brake. This ensures that z-axles with a suspended load
can be restarted without the load dropping.
SBC feedback through SBA diagnostic contact
The 2-channel switching of the brake is displayed over the SBA output. Through SBA, the status of the
SBC safety function is reported for diagnosis,such as to an external safety relay unit.
The SBA diagnostic output displays whether the safe status has been reached for the SBC safety func-
tion. It is set if the following two conditions are fulfilled:
– Switching off of both brake outputs is requested (#SBC-A = #SBC-B = low level)
– The internal diagnostic functions have determined that there is no internal error and both brake
outputs are de-energised (switched off).
At the same time, test impulses occurring at SBC-A and SBC-B are not filtered. The diagnostic output
SBA therefore supplies high level for the duration of these low test impulses.
Check of the SBC safety function
Product overview
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Test inputs #SBC-A and #SBC-B separately from each other and together. The diagnostic feedback
may only be high level when both inputs #SBC-A and #SBC-B are requested. If the signal behaviour
does not correspond to expectations, the system must be transferred into a safe condition within the
reaction time. Time monitoring must be planned in the safety relay unit.
Testing of the SBC safety function with feedback over SBA is required at least 1x within 24h.
• Check SBA feedback dependent on the level SBC-A and SBC-B according to the following table.
#SBC-A (BR+) #SBC-B (BR-Ext) SBA
Low level Low level High level
Low level High level Low level
High level Low level Low level
High level High level Low level
Tab. 4 Check of all SBC levels
Evaluation of SBA
Recommendation: evaluation with every actuation.
• Check SBA feedback at every request.
#SBC-A (BR+) #SBC-B (BR-Ext) SBA
Low level Low level High level
High level High level Low level
Tab. 5 Evaluation of SBC level
Timing SBC
Product overview
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Fig. 7 SBC timing diagram
Legend for SBC timing
Term/abbreviation Explanation
tBrake Mechanical delay of the brake
#SBC-A/#SBC-B 2-channel input for SBC request
tSBC,TP Max. length, low test impulses1) at #SBC-A/B
tSBC,In Max. delay until the related brake output is switched off (≤permissible reac-
tion time when a safety function is requested1))
Product overview
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Term/abbreviation Explanation
SBA Feedback, SBC active
tSBA,Out Max. delay for diagnostic feedback (≤permissible reaction time when a
safety function is requested1) + 10ms)
n Rotational speed
1) see Technical data, SBC safety data
Tab. 6 Legend for SBC timing
Requirements for the brakes
• Check the brakes used for suitability for the application.
As a rule, the brakes used are holding brakes. That means, the brakes are well suited to keep the
motor at a standstill.
The internal holding brake of the motor is also used for the safety function SBC. Observe the following
boundary condition:
– The holding brake must be designed for the load torque to be stopped.
– The specifications for the holding brakes permit a certain movement until the complete holding
torque is reached. This must be taken into account in the design of the vertical axles and configur-
ation of the safety function SBC.
– “Reserves” should be planned for in selecting the motor, e.g.operation at a maximum 2/3 of the
nominal torque. The holding brakes in the motors are usually designed so that, at loads below
70% of the nominal torque, the motor shaft comes to a standstill without coasting.
– Depending on the hazard situation, the holding brake must be designed with a correspondingly
increased nominal torque.
– In designing the holding brake, the additional load torque for the brake test must be considered.
The number of clamping and braking applications is limited for the clamping unit due to wear.
1. Observe the corresponding specifications in the data sheet.
2. Replace clamping unit before the maximum number of clamping applications is reached.
3. Replace clamping unit when the emergency brake features of the clamping unit are used. Pay
attention to the number of permissible emergency braking applications.
Brake test
• Check whether a brake test is required. The DGUV information sheet “Gravity-loaded axis”
provides information on this.
4.1.4 Safety function SS1
Fig. 8 Symbol SS1
The function described here implements the safety function SS1 according to EN61800-5-2.
The safety function SS1 is used when, in the application, the motor must be braked and then the
energy supply to the motor safely switched off, and there are no further requirements for a targeted
standstill of the drive (controlled stop, stop category 1 according to EN60204-1).
Product overview
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Together with a suitable safety relay unit, the following can be achieved:
– Safe stop 1 time controlled Safe stop 1 time controlled; triggering of motor deceleration and, after
an application-specific time delay, triggering of the safety function STO
Requirements of SS1
– Wiring for safety function STO è Fig.13.
– Execute emergency stop command by means of the safety relay unit (either directly by wiring
CTRL-EN or indirectly via a further functional controller).
– The time for executing an emergency stop is known.
– The safety relay unit supports programmable timers and simple logic elements.
Function and application of SS1
The procedure for triggering SS1-t comprises the following steps:
1. Requesting a functional emergency stop (e.g. set input CTRL-EN to low signal).
This causes the servo drive to trigger a braking ramp function and – if present – allows the brake
function to engage at the end of the braking ramp. After completing the braking ramp and upon
elapse of the parameterisable delay time until the brake is closed, the output stage is switched off
functionally.
2. Start of a time-delay element for actuation of STO.
Select the delay time such that the functional braking ramp is completed in closed-loop control,
the holding brake function is engaged, and the output stage is switched off functionally. Other-
wise, simultaneous triggering of STO and the mechanically required brake engagement time can
cause the axis to sag. If the brake is engaged while the axis is still in motion, there is increased
wear on the holding brake (only permitted for emergency braking).
3. Request for safety function STO and – if required – additionally SBC upon elapse of the delay time.
The figure below shows the necessary logic circuit for the safety relay unit:
Logic in the safety relay unit for SS1
Product overview
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Fig. 9 Logic in the safety relay unit for SS1
The delay times are directly included in the reaction time of the system.
Feedback of SS1
The STA signal can be used as feedback for the safety function SS1.
Timing of SS1
Product overview
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Fig. 10 Timing diagram SS1
Legend for SS1 timing
Term/abbreviation Explanation
Timer Delay element in safety relay unit
CTRL-EN Enable signal
tDelay Delay time until STO is requested (drive has safely come to a standstill)
#STO-A/B 2-channel input for STO request
#SBC-A/B 2-channel input for SBC request
STA Feedback, STO active
SBA Feedback, SBC active
t1Braking ramp takes place, speed = 0 (functional)
t2Brake closed, and output stage switched off (functional)
n Rotational speed
Tab. 7 Legend for SS1 timing
SBC request
Product overview
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If there are suspended loads, they usually drop if STO and SBC are requested immediately after the
braking ramp has elapsed since the engagement time of the holding brakes is not insignificant. This
can be avoided if the safety relay unit initially triggers only SBC on expiry of the braking ramp, so that
one holding brake or clamping unit that is present is engaged while the closed-loop controller is still
active. After elapse of the time until the brakes are closed, the safety relay unit can then trigger STO
(time-delayed linkage of the safety functions SS1 èSBC èSTO).
Wiring of the safety function STO to SBC è Fig.14.
4.1.5 Cross wiring of several servo drives
For cross wiring, wire the diagnostic outputs as a ring. Route both ends of the ring to a 2-channel input
of the safety relay unit. The safety relay unit monitors for discrepancies. A maximum of 10 servo drives
can be wired in parallel.
Cross-wiring, example STA
Fig. 11 Cross-wiring, example STA
For cross-wired diagnostic outputs, the condensed state results from a logical AND link. An output of a
CMMT-AS is capable of pulling all other outputs to low signal. A high signal is present at the two
inputs of the safety relay unit only if all diagnostic outputs deliver high signals. The ring-shaped cross
wiring of the diagnostic outputs with sensing at the beginning and end of the signal chain makes it
possible to detect cable breaks in the cross wiring.
At this point, the diagnostic outputs deviate from the closed current principle. Cyclical automatic test-
ing of the diagnostic output by the safety relay unit is therefore highly recommended
è STO feedback through STA diagnostic contactand
è SBC feedback through SBA diagnostic contact.
Product overview
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4.1.6 Error exclusion
Plan suitable action to prevent wiring errors:
– Error exclusion in wiring according to EN61800-5-2.
– Monitoring of the outputs and wiring up to the servo drive by the switching equipment.
4.1.7 Safety relay unit
Use suitable safety relay units with the following characteristics:
– 2-channel outputs with
– cross-circuit detection
– required output current (also for STO)
– low test impulses up to a maximum length of 1ms
– Evaluation of the diagnostic outputs of the servo drive
Safety relay units with high test impulses can be used with the following restrictions:
– Test impulses up to 1ms in length
– Test impulses are not simultaneous/overlapping on #STO-A/B and #SBC-A/B
– The resulting safety-related classification depends on the evaluation of diagnostic feedbacks STA,
SBA è 9.1 Technical data, safety equipment, safety data STO and SBC.
Suitable would be, for example,the safety relaysPilz PNOZmulti, Pilz PNOZmulti Mini or SIEMENSET
200SP with PP-switching output modules.
4.1.8 Interfaces of the PDS
The interfaces of the PDS(SR) (Power Drive System, safety related) to the outside world are:
– Power supply
– Inputs and diagnostic check-back signals
– Movement of the shaft
– Output for controlling a second brake
Interfaces of the PDS
Product overview
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