Festo CMMT-ST-C8-1C-S0 Series Operating Instructions Manual page 5

7.2 EMC-compliant installation
A non-EMC-compliant installation can lead to signal interference on the encoder,
motor or communication cables.
Cable lengths and cable shield
– Only use suitable cables that fulfil the requirements of standard EN 60204-1.
– Comply with maximum permissible cable lengths.
Connection
[X1A] Inputs/outputs for the higher-
order PLC
[X1C] Inputs/outputs for the refer-
ence/limit switches
[X2] Encoder
[X6] Motor phase connection
[X9] Logic power supply and load
voltage supply
[X18] Standard Ethernet
[XF1 IN] RTE (port 1)
[XF2 OUT] RTE (port 2)
1) Adhere to the maximum permissible cable length for the encoder used.
2) Shielded cables from Festo can be used. The shield can only be connected on the motor side.
Tab. 10: Cable lengths and cable shield
Laying cables
Comply with general guidelines for EMC-compliant installation, e.g.:
– Do not run signal cables parallel to power cables.
– Comply with required minimum distances between signal cables and power
cables dependent on the installation conditions. Signal cables must be physi-
cally separated from the power cables to the maximum possible extent.
– Wherever possible, avoid crossing signal cables with power cables or running
them at only a 90° angle in relation to one another.
The encoder cable is e.g. a signal line and the motor cable is a power cable. These
lines must therefore be installed separately.
7.3 Connection example
1
2
3
4
Fig. 5: Connection example
BiSS-C or incremental encoder
1
Max. cable Cable shield
length [m]
25 Not required
25
25 1) Not required but twisted in
2)
pairs
25 Not required but twisted in
pairs 2)
30 Not required
30 Double shielded (CAT 5)
EC motor or stepper motor
2
3 PELV fixed power supply for logic
voltage (24 V)
STO connection example
In this example, the safety sub-function STO (safe torque off ) is triggered by an
input device that makes the safety request (e.g. light curtain).
1 2
Fig. 6: STO sample circuit
1 Input device for safety request
(e.g. light curtain)
2 Safety relay unit
Information on the sample circuit
The safety request is passed on to the servo drive on 2 channels via the inputs
#STO-A and #STO-B at the connection [X1A]. This safety request results in the
2-channel switch-off of the driver supply to the servo drive's power output stage.
The safety relay unit can use the diagnostic contact STA to monitor whether the
safe state has been reached for the safety sub-function STO.
The CTRL-EN wiring shown is not required for the safety sub-function STO.
7.4 Interfaces
Observe the requirements for mating plugs è Manual Assembly, Installation.
7.4.1 [X1A], inputs and outputs for the higher-order PLC
The I/O interface [X1A] is located on the front of the device. This interface fea-
tures:
– 2 freely configurable digital outputs (parameterisable switching logic, PNP logic
or NPN logic)
– 2 freely configurable digital inputs (parameterisable switching logic, PNP logic
or NPN logic)
– 1 digital input for the power stage enable and reset error functions; whether or
not the function will be used can be parameterised in the plug-in (parameteris-
able switching logic, PNP logic or NPN logic)
– 2 inputs for the circuitry of the safety sub-function STO (#STO-A, #STO-B)
– 2 contacts for the circuitry of the diagnostic contact of the safety sub-function
STO (STA-C1, STA-C2)
Detailed information on the circuitry of the product safety sub-functions can be
found in the è Manual Safety sub-function è 1.2 Applicable documents.
The functional inputs and outputs of this I/O interface are used for coupling to a
higher-order PLC, for example. The devices connected to the CMMT-ST all need to
have the same switching logic (PNP/NPN). The configuration
PNP and NPN logic
– PNP logic means that a potential is switched.
– NPN logic means that earth is switched.
The required switching logic can be parameterised using the CMMT-ST plug-in
è online help for the CMMT-ST plug-in.
Signal Level Input
logic 0 0 V internal via pull-down resistor
logic 1 24 V –
Tab. 11: PNP logic
Signal Level Input
logic 0 24 V internal via pull-up resistor
logic 1 0 V –
Tab. 12: NPN logic
4 PELV fixed power supply for load
voltage supply (24 V ... 48 V)
3
4
3 Servo drive
4 Drive axis
Outlet
internal via pull-down resistor
via high-side driver (delivers cur-
rent)
Outlet
internal via pull-up resistor
via low-side driver (consumes cur-
rent)