Watson-Marlow MM420 - Manual (Page 120)

3 Functions Issue 10/06
MICROMASTER 420 Operating Instructions
120 6SE6400-5AA00-0BP0
NOTE
When making the installation it must be ensured that EMC disturbances/noise
cannot result in communication failures/errors or damage to the RS485 drivers.
As a minimum, the following measures must be taken:
1) Shield the motor cable and correctly ground the shield at both ends. If at all
possible, avoid interruptions in the cables. If this cannot be avoided, then it
must be ensured that the shield continues in an EMC-correct fashion at the
connecting locations.
2) All node points must be well grounded (EMC ground).
3) All relay coils must be provided with noise suppression elements.
4) The cables should be routed - as far as possible - separately from other
cables. For RS485 cables it is especially important that they are kept well
away from motor cables.
5) The shields of RS485 cables must be correctly grounded.
If the AOP communicates via the USS protocol, then contrary to the BOP, the
appropriate USS parameters (Table 3-12 and Table 3-13) should be set.
For error-free communications, the appropriate communication parameters
must be harmonized with one another and correctly set - in the frequency
inverter, the connected device and/or in the connected option board. Please
refer to the corresponding Operating Instructions for the AOP and for the
communications modules.
While RS485 communications is operational the power supply must always be
available using pull-up/pull-down resistors.