Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual - Manual (Page 9)

1–3 Introduction
Publication 1771-UM002A–EN–P – May 2000
For specific information required by EN 61131-2, see the appropriate
sections in this publication, as well as “Industrial Automation Wiring
and Grounding Guidelines For Noise Immunity,” Allen-Bradley
publication 1770-4.1
Open style devices must be provided with environmental and safety
protection by proper mounting in enclosures designed for specific
application conditions. See NEMA Standards publication 250 and
IEC publication 529, as applicable, for explanations of the degrees of
protection provided by different types of enclosure.