Well, now at least the device status always remains CONNECTED, but I'm still receiving Bad data
From what I could see in Wireshark, the queries seem correct.
Could it be a problem processing the responses from the device? I understand that the response also sends 0xF834 in the address pair. Perhaps the driver is expecting responses from ID:300 and that's why it's not processing them.
Anyway, I sent you an email with the Wireshark captures and the wrapper.log file in case that helps.
The ELAM spec doesn't actually show sample message frames, but it modifies function codes for bulk reads (0x01, 0x02, 0x03, and 0x04) such that the response message reports the byte count as a 16-bit value instead of an 8-bit value. The ELAM spec hints at this but doesn't actually declare it. But since ELAM mode supports reading up to 2500 registers in a single request, the byte count cannot possibly fit in an 8-bit value.
It will take some more code surgery to support this. I'll report back later, probably tomorrow.
Thank you for playing out in real time over the last couple days why I don't support bastardized "Modbus" implementations for hardware that doesn't even exist any more
That's great to hear, Phil.
Is there any chance of supporting 2500 register readings in the future? (Maybe not 2500, but at least 500) This would be very useful for reading the controller's dynamometrics cards.
By the way, we have +2400 of these controllers in our oil field
Well, nobody donated a real unit for my lab, so working out the details is hard to hide.
No, not really. Too many other, more valuable, prospects in my to-do list. FWIW, there's just not much performance to gain with it, unless you are trying to run across a WAN. And that is something I don't want to encourage at all.
Ok, that means Lufkin didn't include function codes 1 and 2 in the 16-bit bytes-to-follow adjustment. Let's just say I'm less than impressed with Lufkin's ability to write a specification.
Give me a minute... Done. Next try:
For Ignition v8.1: v1.1.13.251061916
Side note: This cherry-picked neatly into my v8.3 version, and is passing my QA, but I have no ELAM hardware to test the ELAM part..... cough
Success! I was an idiot and was using Modbus TCP After re-reading the documentation, changing it to Modbus RTU over TCP and adding that extra :57600N1 it is now pulling data!
Now i just need to get the login to the serial converters to see what the settings are supposed to be!
After re-reading the documentation, changing it to 
