SEW-Eurodrive MOVISAFE DCS B Series

Manual – MOVIDRIVE® MDX61B Safety Module MOVISAFE® DCS..B Option
65
5
Connecting the position and velocity sensors
Installation
• If both encoders are connected to the monitoring system through shared mechanical
parts, the connection must be positive and may not include any parts that are subject
to wear (chains, toothed belts, etc.). However, if parts subject to wear are used, you
must install additional monitoring systems to check the mechanical connection of the
sensors (e.g. monitoring function for a toothed belt).
• If position processing is enabled, you must use at least one SSI absolute encoder. If
you use only one SSI absolute encoder, connect it to X85 "Encoder 2".
• An internal number format is used in the input fields "Position", "Velocity" and "Accel-
eration" when the monitoring functions are configured. This can lead to rounding of
the entered values.
5.10.2 General installation notes for encoders
• Maximum length of encoder cables:
100 m (328 ft) with a capacitance per unit length ≤ 120 nF/km.
• Core cross section: 0.2 – 0.5 mm (AWG24 – AWG21)
• Use shielded cables with twisted pair conductors and make sure they are grounded
on both ends over a large surface area:
– At the encoder in the cable gland or in the encoder plug
– At the inverter in the housing of the D-sub connector, or
– At the metal clamp / strain relief at the bottom of the inverter
• Observe the notes in chapter "Measures for electromagnetic compatibility (EMC)".
5.10.3 Combination of various encoder types
You always have to provide the DCS..B option with two encoder signals. You can
connect the encoders directly to the X84 and X85 terminals of the DCS..B option. You
can also use the encoder values of MOVIDRIVE
®
B via the backplane bus. Whether one
or two encoders are used for monitoring mainly depends on the required performance
level and has to be assessed separately. Furthermore, measures have to be taken
against a possible malfunction of an encoder system if the malfunction can negatively
influence the application (example: position processing with only one SSI absolute
encoder). Various encoder types can be combined depending on the specific applica-
tion. Observe the following notes.
If you change the encoder configuration at a later date in the MOVISAFE
®
Assist/Config
software interface, the existing parameters for the monitoring functions might no longer
be compatible with the new encoder configuration. In this case, check the parameter
settings and value ranges of all the monitoring functions in use.