Red Lion MODBUS register mapping (for Arduino)

[John Morris]

Like sands through the hourglass, so are the days of our lives.

 

[arlenjacobs]

MgsModbus

I had troubles with that library, and wasn't fond of how it was structured.

Not to feed your appetite of frustration, but take a look at this one
https://github.com/andresarmento/modbus-arduino/issues/18
I got that working with an Ethernet chip.
But the offsets are limited to 9999, and I see nothing to support floating point.


In the end, I decided to just scale my values by 100 into/out of the registers (temps 0 - 100C)

 

[Mark-]

My my what problems you must have to unnecessarily be condescending/rude to me twice, after I already answered OP's question no less.

My my, you decided to get upset with my post. You started this with your snarky name calling. I was trying to give the OP correct data. You "already answered" had flaws; that was why I posted.

You obviously didn't read my response regarding the water cut meter I was talking about, as your response completely misses the point.

I read your response and still it is nothing but words. Words that continue to indicate the extra digit was added for a reason which is not true. Provide a link to the flawed manual so we can see what you are describing.

Have you read the MODBUS protocol specification?

"Enjoy" having PeakHMI on the list of companies I tell people never to deal with.

 

[phuz]

Can we please not clutter this thread with this back and forth stuff? Maybe keep it in a PM?

I had troubles with that library, and wasn't fond of how it was structured.

Not to feed your appetite of frustration, but take a look at this one
https://github.com/andresarmento/modbus-arduino/issues/18
I got that working with an Ethernet chip.
But the offsets are limited to 9999, and I see nothing to support floating point.


In the end, I decided to just scale my values by 100 into/out of the registers (temps 0 - 100C)

Thanks, I was thinking I'll just do the same. I'm rather pleased I got it working. In fact, the surprising part, for me, is that the response time between the Arduino and the PLC is MUCH quicker using the Red Lion as a gateway, rather than going directly to the modbus-supporting AB controllers (L18ER) using their sample code (http://search.rockwellautomation.co...ie=UTF-8&ud=1&exclude_apps=1&site=sample_code)

While the Red Lion gateway method was almost instant, the direct method was about 500ms lagged.

 

[arlenjacobs]

Can we please not clutter this thread with this back and forth stuff? Maybe keep it in a PM?



Thanks, I was thinking I'll just do the same. I'm rather pleased I got it working. In fact, the surprising part, for me, is that the response time between the Arduino and the PLC is MUCH quicker using the Red Lion as a gateway, rather than going directly to the modbus-supporting AB controllers (L18ER) using their sample code (http://search.rockwellautomation.co...ie=UTF-8&ud=1&exclude_apps=1&site=sample_code)

While the Red Lion gateway method was almost instant, the direct method was about 500ms lagged.

I also am using the CompactLogix with their Modbus code; not pretty or easy.

One problem/gotcha with the "andre" library I linked is that it will not allow an open connection; it closes after each request.
My plan was to fix that but have not gotten around to it yet.