Hi there,
I only have a small number of brochures for the systems I’ve developed. Working on 2 new NETMF projects just now and one is another G120 based and the other is G400.
Drop me a PM with your email address and I can send you what I have.
Hi Zan,
I hooked up the scope to the output from the MAX13487 and used the decode function on the scope to try and show what was on the RX line to the G120. The scope was able to decode the 3 different baud rates as shown by the attached images.
The G120 is still not able to receive the 38400 cleanly with only a few of them being decoded. The scope shows the data is good. Something is not right with the timing on the G120 side. A G120 to G120 is GOOD.
I need to setup the 2 G120’s to transmit to and from each other and see what the timing for 38400 looks like.
And this is decoding the reply when the G120 does manage a decode. The timing of the byte is the same around 208uS
The first one is the RX input to the G120 and the second image is the output from the G120 into the MAX13487.
Everything looks good so can’t see why this is not working. Even the voltage levels are good and the edges are clean.
@ Dave McLaughlin - from my experience, even when we were seeing the good signal across the wire on the scope, I could not get it past the 38.4K. To even get it to work on 38.4, I needed the high powered opto couplers.
Once we upgraded to high speed optos, the whole setup started working and I can confirm the speeds reported with no issues up to 128K and beyond.
I do not have the new boards to do a full test, but once I do in couple of weeks, I will provide the setup that I have in place that works with the high speeds and the MAX IC.
One thing I never spotted first time was the over and undershoot on the edges at 38400. I need to connect this back up and zoom on these and see how they look.
Clients messy wiring and setup for testing my board with their PLC. They assured me that it won’t look like this for the final builds. I hope so. 
It all worked and this will be deployed at the well site in the coming week or so.
4 Likes
Not too bad, I have seen some spaghetti mess with my customers…
Hope it all works well in the end, nothing like the real test out in the field.