from the Forum department...
Proximity sensor wiring to PLC/DCS
Sensor technologies. topic
Posted by VK Aggarwal on 6 April, 2009 - 10:20 pm
Can someone let me know how to wire Namur, 2 wire and three wire pnp/npn proximity sensors to DCS/PLC assuming the field to be safe area.I would like to wire these sensors to conventional digital input cards of PLC/DCS.


VK Aggarwal

Posted by Sriram on 8 April, 2009 - 3:49 pm
What kind of digital input card are you using? Is the power for 2-wire coming out of the PLC or is it external?

In general, for a 2-wire switch, the power goes to the positive terminal of the switch and the negative goes back to the PLC. Ensure the same reference is used on both PLC/DCS and the switch. For a 3-wire, the power and common goes to the switch and the signal back to the PLC/DCS. Even in this case its very important to maintain the reference voltage.

Hope this answers your question.


Your use of this site is subject to the terms and conditions set forth under Legal Notices and the Privacy Policy. Please read those terms and conditions carefully. Subject to the rights expressly reserved to others under Legal Notices, the content of this site and the compilation thereof is © 1999-2014 Nerds in Control, LLC. All rights reserved.

Users of this site are benefiting from open source technologies, including PHP, MySQL and Apache. Be happy.

Equal bytes for women.
Advertise here
our advertisers
Help keep our servers running...
Patronize our advertisers!
Visit our Post Archive