Internet PLC Forum

General => Technical support => Topic started by: asitsaha on May 03, 2014, 05:55:50 AM

Title: Analog Channel Nano-10 loading
Post by: asitsaha on May 03, 2014, 05:55:50 AM

Wiring done as per Nano-10 user manual. We need to convert 4-20 ma to voltage. I have used 253.16 ohm resistance. The 4-20 ma channel (ABB PLC analog output) supplying the current is getting loaded. Pl suggest the solution

Title: Re:Analog Channel Nano-10 loading
Post by: support on May 03, 2014, 10:59:07 PM

What do you mean by getting loaded? The resistors you use is connected in parallel to the 20K ohm internal impedance of the AI which presents a 250 ohm load to the 4-20mA current source which will convert it into 1 to 5V that the Nano-10 can read.

Are you using a 2-wire loop-powered type of analog output from your other device? If so you will need to wire it similar to what's shown on this forum thread:

http://www.triplc.com/yabbse/index.php?board=2;action=display;threadid=347