6
Electrical installation
Connecting the incremental encoder EI7.
Manual – EtherCAT
®
Interfaces, Field Distributors
59
6.8
Connecting the incremental encoder EI7.
6.8.1
Area of application
With the MFE72A EtherCAT
®
interface and the built-in EI7 encoder from
SEW‑EURODRIVE, you can implement simple positioning based on a higher-level
controller. Just connect the built-in EI7 encoder to the MFE72A EtherCAT interface
and evaluate the position with a 32-bit counter. This design allows non-dynamic posi-
tioning with an accuracy of approx. ¼ of a motor rotation when using the EI7C en-
coder. However, direct position control or time-critical positioning is not supported.
With this design, you can replace applications that were previously implemented with
a rapid traverse/creep switch with initiator evaluation. Variable evaluation of any actual
position and specification of different speeds and acceleration ramps gives you
greater flexibility.
When in 10-PD mode (see
chapter "Process data object configuration"" (→
the counter and thereby the current actual position is sent to the higher-level controller
and evaluated.
6.8.2
Features
The EI7. incremental encoder offers the following features:
•
HTL interface
EI71:
1 pulse/revolution
=> 4 increments/revolution
1)
EI72:
2 pulses/revolution
=> 8 increments/revolution
1)
EI76:
6 pulses/revolution
=> 24 increments/revolution
1)
EI7C:
24 pulses/revolution
=> 96 increments/revolution
1)
1) due to 4-fold evaluation
6.8.3
Technical data of encoders
Technical data of encoders
Encoder signals (2 tracks)
Tracks A and B
Phase sequence
90° ± 20°
Pulse duty factor
1:1 ± 20%
Max. pulse frequency
120 kHz
Connection track A
Terminal X20/19 (DI0)
or M12 plug connector (DI0)
Connection track B
Terminal X20/22 (DI1)
or M12 plug connector (DI1)
Reference potential
GND on PE potential
The counter counts up for advancing A track and down for advancing B track.
25809148/EN – 01/2019