Sign in to follow this  
Followers 0
Linhvct

[Help] Analog signal error?

5 posts in this topic

Dear all, I use a level measurement device [AKS4100 - Danfoss] and a motor-ride valve [iCM 20 - Danfoss] to control the liquid level in a tank. The 4-20mA analog signal output is set to AKS4100 in order to feed-back the current liquid level to CP1W-ADxxx, the analog input extension unit. Everything was ok till an error occured after 5 days from the first time system started. The PLC often receives the 3.6mA feed-back signal from AKS4100 (the correspondence DM memory of this analog input signal has a value of -160, prescaled, it is 3.6mA). I thought the liquid level was just at 0%, so I checked the real level in the tank, but the level was about 40-50%. I'm very confused in this situation. Can you tell me why this error takes place and what I should do to fix this error? PS: I've read the AKS4100 user's guide and I found that it does mention "error output set to 3.6mA" in technical data "current output load", but I can't understand what it means. I attach this document in case needed. Thank you very much!

Share this post


Link to post
Share on other sites
Error output is when the sensor electronics detect a fault. Could be anything from out of range to sensor breakdown. Are there any error codes on the transmitter display? Geir

Share this post


Link to post
Share on other sites
Unfortunately, this sensor is completely covered by foam, polyurethan, in order to keep it working in a very harsh environment; low temperature ice frezzing environment when the machine works and high humidity, wet environment when the machine stops. So, I'm unable to see what the error codes on the transmitter display. Thanks Geir, I'll try to find out what happens to this sensor.

Share this post


Link to post
Share on other sites
The display is optional, but this is from the tech info, does not say how to fix it thou :( If the error is not obvious, I usually start troubleshooting by resetting to factory before making a fresh configuration. ? Device status (markers) on HMI display 1 = Hardware problem (any hardware problem making the device unable to provide a correct measurement (communication, memory problem…) 2 = No Reference Pulse 3 = Low Voltage or Measurement Old 4 = Level Lost Note: The current output will be set to 3.6 mA whenever the AKS 4100/4100 detects an error like: "Level lost", "Overfill error" or "Reference pulse lost". Geir

Share this post


Link to post
Share on other sites
I think the error may possibly be "level lost" because it occurs when the tank is empty (the machine turns from on to off then the liquid is pumped out from the tank to another tank for safety). But I still wonder why this error does not auto-reset when the liquid level in this tank rises up again, and I must reconnect the 24VDC power supply to it again to push it work (this's like reseting the sensor) Edited by Linhvct

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0