Appendix A • Abbreviations
Appendix A
Automation PC 510 User's Manual V 1.01
181
Appendix A
1 Abbreviations
Abbreviation
Stands for
Description
Normally closed
A normally closed (N.C.) relay contact.
NC
Not connected
Used in the description of pinout if a terminal or pin is not connected to a module.
ND
Not defined
In data tables, this stands for a value that has not been defined. Because a cable
manufacturer does not provide certain technical data, for example.
NO
Normally open
A normally open (N.O.) relay contact.
TBD
To be defined
Used in technical data tables when certain information is not yet available. The
value will be provided later.
Table 184: Abbreviations used in this user's manual