Message instruction destination tag help

Hello, I'm trying to read a parameter from a Power Flex 525 drive to monitor output current in order to detect a jam condition in carousel filler. I'm following the handy example in Power Flex manual but am confused about the destination tag. I'm creating a tag called Output_Current but what should my data type be? With an INT it makes a tag with a + next to it and it's full of BOOLs.

I want my Output_Current to be a number so I can stick it on an HMI and look at it. Eventually, after I determine what value corresponds with a jam condition, I will use a comparison instruction to enable hard stop of the filler. I'm new to this rxlogix 5000 stuff. Will an INT data type tag work? How do I get a normal number instead of a tag full of 16 BOOLs?

Attached is the example in the 525 manual. Controller is a CompactLogix and I don't have the ability to test the project on a spare controller.

Thank you

I don't know if an INTeger tag would work, the manual should cover that. You just need to make sure the data type match. If it's a 16 bit integer at the drive, then your destination data type needs to be a 16 bit integer.

As for the the + symbol, it would always be there because an 16 bit integer is made up of 16 bits (or Boolean)

ETA: I take a quick read at the manual. I would suggest you use the Add-On-Profile if possible. By using that, it would create all the necessary tags for you and there would be no need to use explicit messaging, I think.

The Output Current is a 16 bit parameter requiring the use of a INT data type. My confusion is that I'm familiar with the N7 file from rslogix 500 so how would I grab the value from the Output_Current tag in 5000? If could run the project on a spare controller I could look at the tag and see where the integer value it at but I don't have that option. Within the Output_Current + drop down, where would my output current parameter be?

Specifically,what would be the Source for a greater than comparison instruction? (Output_Current +) or (Output_Current.0) (Output_Current.1) (Output_Current.2... Output_Current.15)

Thank you

An INT will work. All the Integers in RSL5000 will show you the Booleans, it is the default action, so don't worry about that.

I agree with harryting, if you get the Add On Profile, the Current Output should be listed in the Input Parameters.

If you want to proceed with the way you are presently doing it, that should be fine. Do the Compare with the Tag Name. i.e. Output_Current.

Stu....

Add On Profile? Is this similar to an Add On Instruction but made up of tags or something instead of instructions/logic?

Googling this time now.

Have a look here and search for "Drive AOP".

http://compatibility.rockwellautomation.com/Pages/home.aspx

Stu....

LowRange,
I've done the exact same MSG instruction recently to gather the drive amps from a PF525 into my 1756-L71. Your Output_Current tag will need to be type INT and the data will be in xx.xx Amps units.

First off, you need to have the drive defined in your I/O configuration. This is where the AOP comes into play.

Like working with SLC & PowerFlex7 series drives, DataLinks are provided to read/write data between PLC & VFD. In the Logix based processors, this is setup within the module properties, general tab, Module Definition and requires a download to the PLC. With my process, I do not have the opportunity to take the PLC offline at will so I opted for the MSG instruction.

Not sure about this situation, but in many cases it is helpful for us if you share make/model/part number for the devices you're working with. Sometimes firmware version can be a game changer as well. Glad you're part of the forum!

See thread

Thanks for the input guys. I opted to read multiple parameters by following the example in my PF 525 manual. I also have the 525 embedded Ethernet so adding the drive to my I/O configuration was never an issue. Attached is a screenshot of the section in the manual demonstrating how to read multiple parameters. Essentially you're messaging to the drive to grab multiple 16 bit parameter values and then stick them into an INT array. Identification of the individual parameters is done with the parameter instance number and the value is displayed below the instance number.

I'm going to throw a few numerical displays onto the HMI, address them to my drive parameters and play with the line Sunday night when it's not running. If all goes well I should be able to get some useful information from the drive when a bottle jam occurs. If I can identify bottle jam conditions and halt the machine then this prevent the bottle jams from becoming metal to metal contact, shaft bending filler crashes.


Thanks a lot guys.

I've got a chance to go online with the controller and things are not going as planned. In my parameter_read_request tag the values are all zeros instead of matching the requested power flex parameter numbers (2,3,4,5,17). Also, my parameter_read_response tag for drive parameters are all -32768 with parameter values of 22.

I'm assuming it's not happy about not being told from which parameters to grab values but I followed the example exactly. How would the scattered read message know what parameters from the drive I want?

LowRange said:

In my parameter_read_request tag the values are all zeros instead of matching the requested power flex parameter numbers (2,3,4,5,17).

Click to expand...

I believe you need to enter in those numbers manually into your parameter_read_request tag. This tells the drive which data to return. Make sure you use the even numbered elements, like in the manual's example.