-1.QNaN with compactlogix controller

Does other reading works well? Or it is just this register you can't read? Send us raw answer of Modbus reading of this register and we can figure it out...
 
Post the contents of the sints before you copy it to a real.

Also, What value does the meter say it should be when you use its keypad and screen?

Are you sure this is the same energy meter as the others and not an updated model as the old one is obsolete?

SINT shows -1.#
Meter screen shows somewhat around 32.853 Giga Watt Hour.

And other meter are same as this one. I have rechecked this today. Everything is same including firmware revision.

Now only thing i can try is, Can instal new meter instead of this with same address and can have trial error.o_O
 
This link shows that accumulated energy is stored in 64 bit registers, if you are reading 3204 and onward. Sorry about the complex link, I couldn't get to it without going through Google:
https://www.google.com/url?sa=t&rct..._v2.1.0.xlsx&usg=AOvVaw1KQL427948lofQBlASDntU
Different meters store the same data in different formats, so you can't directly compare one with another.

I am not comparing meter to meter. I am comparing apple to apple. And that is what i am unable to understand that why only this one is not working...
:unsure:
 
Does other reading works well? Or it is just this register you can't read? Send us raw answer of Modbus reading of this register and we can figure it out...

Other readings like Voltag, Current, KW, PF reads perfectly well. Only thing i am unable to get is KWH, KVARH, KVA, KVAR.
Modbus raw data it self shows -1 value.
 
So time for some simple diagnostics. Temporarily swap the Modbus Address of a fully working meter with the part working meter, obviously making sure that it won't cause problems anywhere else in the system. If the problem stays at the original Modbus address then the problem is in your code. If the problem moves to the new Modbus address then the problem is in the original meter. Swap them back to original again. Probably stretching the apple thing a bit far, but there are Bramleys and Granny Smith, etc. Check the firmware versions of the meter, maybe this one isn't quite the same type of apple as the others or maybe it has a worm and is just faulty.
 
Other readings like Voltag, Current, KW, PF reads perfectly well. Only thing i am unable to get is KWH, KVARH, KVA, KVAR.
Modbus raw data it self shows -1 value.

I'm afraid that it is not raw data, or at least I was not clear enough. Send us Modbus response code you are obtaining. I'm afraid that you are receiving Modbus exception code/response.
 

Similar Topics

Hello, I am average in automation, we had power outage in our factory, and one of the conditions on the SCADA was 0 regardless of any change so...
Replies
13
Views
435
Hi All, I have relatively obscure problem with floating point numbers. My setup is a CompactLogix with a Prosoft MVI Modbus TCP Card. The...
Replies
4
Views
14,470
I noticed in a PLC 5/04 program I have a 1.#QNAN as a value for a floating point number. After some Googling I have come to know that QNAN stand...
Replies
6
Views
12,008
Hello all, and thank you in advance for any assistance you may be able to provide! This is my first post, so if I need to reformat or change...
Replies
0
Views
14
We are trying to poll data coming from a PLC for remote monitoring we have the IP address of the PLC and the default port number and the path is...
Replies
25
Views
418
Back
Top Bottom