Analog Output on MicroLogix 1400 1766-L32BWAA

[Mickey]

Post your .RSS file if you can. Zip it first.

Page 6 briefly talks about the analog out channels. It does show a span up to 32760. With that it is possible that if you enter a value of 32767 that you would get 0VDC.

http://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1766-rm001_-en-p.pdf

That is for expansion modules. The raw data for the embedded analog outputs is 0-4095. See pdf

 

[Geospark]

Are you Online to the controller when making the changes to the Output word(s)?

What Base is selected for the controller under the IO Configuration?

To check, go to IO Configuration and double-click on Slot 0.
Here, under the Embedded General Configuration tab, the Base/Type should be set to BWAA Base for your analog based L32BWAA controller. The default is Any Discrete Base, which do not include analog.

Also, a quick and easy way to figure out roughly what voltage to expect at the output is to use the following formula...

10V
----- X Output Value = Expected Voltage
4095

Example:

Output Value = 1000

10V
-----
4095 = 0.0024420024420024

0.00244 x 1000 = 2.44v Expected Voltage

Regards,
George

 

[kennedy6277]

Are you Online to the controller when making the changes to the Output word(s)?

What Base is selected for the controller under the IO Configuration?

To check, go to IO Configuration and double-click on Slot 0.
Here, under the Embedded General Configuration tab, the Base/Type should be set to BWAA Base for your analog based L32BWAA controller. The default is Any Discrete Base, which do not include analog.

Also, a quick and easy way to figure out roughly what voltage to expect at the output is to use the following formula...

10V
----- X Output Value = Expected Voltage
4095

Example:

Output Value = 1000

10V
-----
4095 = 0.0024420024420024

0.00244 x 1000 = 2.44v Expected Voltage

Regards,
George

I am online and in RUN mode when changing values in the data table manually and with my program. Also I do have the correct settings in the IO Configurations but still 0V across OV0/OV1 and COM ANA.

 

[ndzied1]

One more idea, how many places in the program are you writing to the outputs?

You could be over writing what you think is there.

 

[Geospark]

...changing values in the data table manually and with my program...

But not at the same time right?

When you manually enter a value in the Output Data Table word O:0.4 or O:0.5 the value is static I take it? For example, you type 1000 and hit enter and it changes to 1000 and stays at 1000. Else you wouldn't go off looking for voltage I assume?

There is no way the program is overwriting anything you are manually entering so the value reverts to say "0"?

If you do have programming for this output what is controlling it? PID, analog input scaled to output?

Is the program routine inhibited from modifying the output value while you are manually modifying it?

Again, I'm sure you would notice if the program was interfering with the output value, but I have to ask these relatively simple questions just in case. We have had many cases here before where users were doing something fundamentally basic, yet missing a simple step or overlooking a programming glitch. It's not that I think you are ignorant to these facts but without any prior knowledge of your level of expertise I have to assume you know little to nothing and cover the basics.

EDIT: ndzied1...exactly what I'm thinking.

Regards,
George

 

[Mickey]

I'll ask again, please post your program it's .rss file (zip it first)

 

[kennedy6277]

I'll ask again, please post your program it's .rss file (zip it first)

This is what i have right now. Its a very simple program.
I just tried attaching a load to the output but still nothing.

 

[Mickey]

I'm not seeing anything wrong, it should work.

Double check your meter?

That is quite possible since the unit is from a parts room at my school. What can i do if this is the case?

Time to punt.

 

[JohnCalderwood]

Analog Output ch 0 is O:0.4
Analog Output ch 1 is O:0.5

Full scale (10V) is 4095

COM ANA is 0v and OV0 and OV1 are the +ve channels

I use my two channels to send a speed reference to 2 Danfoss VSDs

 

[dburnum]

This may be a dumb question, but how are you sourcing your voltage to the output? Are they internally powered? or fed from a voltage source?
Nevermind: They appear to be internally sourced.

 

[Mickey]

I had a bad pdf in my psot #16 above. Here is what it should have been.

Others have already said it though.

 

[kennedy6277]

I believe I have found the issue. I think someone before me shorted the terminals and blow a transistor. I think am just going to switch to a controlLogix. Thanks for your help everyone. :site: