×
Log in
Get Started
Travel
Technology
Sports
Marketing
Education
Career
Social Media
+ Explore all categories
Report -
Your First PLC · two basic contacts are N.O. contacts and N.C. contacts. Switches, relays, timers, counters and other devices have contacts A "N.O. contact" is a "normally open"
Select
Pornographic
Defamatory
Illegal/Unlawful
Spam
Other Terms Of Service Violation
File a copyright complaint
Please pass captcha verification before submit form