V570 w/EX-A2X

[Eric @ SM]

It's been a while since I've had to deal with this, as I've changed companies over a year ago, but one of my old customers contacted me and is having an issue with a V570-57-T20B that is plugged into an EX-A2X adapter.  The adapter has a DI16 and RO8 attached.  He is getting a blinking COM light, and obviously because of that nothing is working.  These components are all installed on a fuel tanker truck, and they control the fuel delivery systems, so obviously this is a bit of an issue.  He's replaced the EX-A2X, same result.  Could this be a cable problem, or a problem with the DI16 (it is first in line after the EX)?  Installation is a good 1k miles away from me, so it's not like I can just go look at it...

[cantcliff]

Could be a wiring issue.

 

*edit*

 

I would double check some of the 0v lines to make sure they are all on commons.  I had issues with communications once that was caused by that.

 

[Eric @ SM]

I can have him check the 0V side, but I doubt that to be the issue as everything has power and this is a straight 12VDC system ("L" model expansions).  I'm beginning to suspect the expansion cable but again, since I can't just go look and check myself it's hard to make that determination.

 

Anyone have the pin-outs on that cable?  It is a custom made (~28ft long) cable.

[cantcliff]

Even if everything has power, the EX-A2X *requires* that the communications module and the PLC are on the same power supply (Page 5 of the documentation for the adapter). I've experience this issue in my own box when first using on of these as I missed that portion of the documentation as well and used a secondary power supply to power the EX-A2X but was having comms issues like you're having.

 

Both units must power up simultaneously as well.

 

How long have they been running that cable?  If they wired it as a standard RJ45 network cable it won't work.  There is definitely something different about the EXL-CAB100 as even plugging it in backwards can cause communication issues (Personal experience for not reading labels).

[Eric @ SM]

They do get powered by the same source, as I've experienced the timing issue before.  The cable is one I made myself shortly after the EX-A2X was released to replace the EX-A1, so while I know it uses an RJ cable and ends, I know it only uses 6 wires of the 8 and that they are different end to end.  I was going to have him make a new cable.  I actually just realize a customer sent in an EX-A2X so I can get the pin assignments myself.