Trying again: wireless transmission w/a PLC5

[mdfoust]

Hi everyone/anyone,

I posted yesterday on this question and was probably too vague. I will try to describe again. I have a PLC5 acting as a master in a wireless communication setup with Phoenix (Omnex) radios. I am successful at retrieving analog data, but can't read the digital. From discussions with the reps, I have configured the serial port correctly and it appears I am transmitting and receiving data between the radios. The analog register values are being sent to starting register N7:16. The digital data in the radios begin at N8:2. For my first read msg I give the target address as 0. When I do this I am able to mirror the data into register in the PLC5 just fine for the analog. But, because the target address must be octal, I do not know how to retrieve the data from N8:0. I have tried several things that haven't worked. Any help/thoughts on this is appreciated.

Thanks,
mdfoust

 

[93lt1]

For one thing...

N8:xx is not a possible address in a PLC5. Data file #8 is fixed as "floating point" it would be F8:xx. If you have digital data it would most likely be in an N or B file.

 

[mdfoust]

The N8 register resides in the radios. I am just trying to read this into the PLC5. I can read the data into N7 registers from the msg block.

 

[Ken Roach]

It would be great if you would post the part numbers of your Phoenix/Omnex radio products. I *think* that you are using their I/O system that emulates PLC/SLC registers, rather than acutally connecting a PLC or SLC to their serial radios.

You also may be misunderstanding the difference between a DF1 network "address" and a data table "address". The DF1 address is the node number for the emulated controller at your radio location. The data tables in a PLC/SLC controller themselves have File Numbers (3,4,5,6,7,8, etc) associated with standard data types (Boolean, Timer, Counter, Control, Integer, Floating-Point, etc).

The most likely culprit I can see is that you are trying to address "N8". In a PLC-5 or SLC-500, File 8 is always a Floating-Point type file, so your MSG instruction might not allow you to put in such a mismatched file number / file type in the Message instruction configuration window.

If possible, I'd recommend changing the digital data to mapping into File N9, or File N10.

 

[mdfoust]

I will have to get back to this tomorrow Ken, but I believe I have the node and table addressing correct. I must clarify that I am not trying to address any registers in the PLC5 as N8. I understand the associated dedicated file types and their designated numbers. The N8 registers are in the radios, holding the digital data that is read from the radio, into the PLC. I am gone for the rest of the day, but will get back to this in the morning.

Thanks for your input,
mdfoust

 

[Ken Roach]

But the PLC-5 in which you are configuring the MSG instruction *thinks* that you are addressing another PLC-5, not an Omnex radio. The PLC-5 knows that another PLC-5 can't have an "N8" file, and therefore I don't think it will even send such a request via DF1 protocol.

 

[mellis]

While I don't recommend it as a good practice, you *can* delete the default F8 file in a PLC5 and replace it with a new N8 file.

 

[rsdoran]

I am curious..How?

While I don't recommend it as a good practice, you *can* delete the default F8 file in a PLC5 and replace it with a new N8 file.

Is this something you can do with just the PLC5? Can it be done with an SLC500? I looked but havent seen a way to delete a "default" data file.

I doubt I would ever want to do this but you never know there may be a time when its necessary for unknown reasons.

 

[mellis2]

Ron,

I don't have a PLC5 here to check with to make sure it will download, but RSLogix5 didn't have any problem with me doing it offline earlier (when I posted). I just right clicked on the data file (F8 in this case) and remove or delete was an option. Then I added a new file and choose the type to be integer.

I do seem to remember running into this in the past in a running processor, but I hate to rely too much on my memory for details like that.

I didn't check for RSLogix500.

(not logged in because I'm not on my computer)

 

[Contr_Conn]

You can delete F8 data file in PLC5 offline.

But looks like RSLogix 500 does not have this option.