3 Nov 23

Paul McGill:

1  1) Let’s label the RJ-45s as “J1A” coming from serial port 1 on Digi #1, “J1B” coming from serial port 1 on Digi #2, and “J1C” going out to the DTE device. The same for “J2A”, “J2B”, “J2C”, etc. This way we won’t have to pull out the schematic to know which RJ-45s are linked. The Digi ports are labeled 1–4 from left to right, so we could stick with that arrangement too. Does that make sense?

1  2) Let’s designate the power port J5 and label it with “+”, “-“, and “24 VDC” so we don’t need to see the schematic to wire it.
 
1   Change the Phoenix connector to vertical jack with plug

10 Nov 23

Designed in jumpers to swap TXD and RXD on the output side of the relays.

Sent graphics to Paul McGill

15 Nov 23

Feedback from Paul McGill:

Thanks for continuing to work on this despite my lack of feedback. I’ve been struggling with the fact that according to the EIA RS-232 spec, a line labeled TX may be either an input or an output, depending on whether the device is DTE or DCE. There’s no way to tell if a particular OEM sticks with the EIA standard or just always labels outputs as TX. The only way to be sure is to power up each device and check the pins with a DMM.

In lieu of that, I agree that we should just remain flexible and put in the jumpers. Would you please complete the layout, given the pinout for the Digi 10 pin ports shown in section 6 of this doc?

https://hub.digi.com/dp/path=/support/asset/portserver-ts-m-mei-quick-start-guide/

We’ll want to pick up pins 5, 6, and 7. Note that we’re using 8-pin connectors, so the pin numbering won’t match the 10-pin connectors on the Digis. Also note that we’re picking up signal ground (SG, pin 7) and not ground (GND, pin 4) as the latter seems to be connected to the DB-9 shell.

Please take your best shot at the schematic and we’ll both look it over until we’re convinced it’ll work for us.

13 Dec 2023

From Paul McGill:

Everything looks really good except for the RJ-45 pin numbering. The Digi has 10 pin RJ-45s but we'll be plugging in 8 pin RJ-45s, so we have to account for the difference.

Digi  pins 5, 6, and 7 will show up on an 8 pin connector as pins 4, 5, and 6 because we’re skipping pin 1 (and 10). Please stare at the diagram below until you’re convinced because I may still have made a mistake.

We should also make sure that pin 1 on the 8-pin RJ-45 you’ve selected is on the same side as the Digi’s 10-pin RJ-45. You would think that would be standardized but stranger things have happened. Would you please check that?

To Paul McGill:


   I'm attaching a sketch of " rotating " the RJ45 graphic which you sent; with the tab UP, pin 1 is on the right side, which matches the pcb's RJ45.  Also including a  pdf of the updated schematic.

   The output RJ45's also reflect the updated pinout.  

From Paul McGill:

It all looks great now and I guess we’ve stared at this for long enough. Go ahead and fab some boards and we’ll try them out next year. I guess we need two built assemblies (one to deploy plus one spare). I leave the details up to you as to how many blank PCBs you want and how many spare components over the minimum needed.