V890 RSC card - different somehow?

Question

I use Aurora Aries cards in my console server. I ran into a problem when I ran serial lines to my new v890's, and I was hoping someone here might have the answers. Here's some data points:
The serial management port on the v240, the serial mgmt port on the RSC card that ships with the v440, and the serial mgmt port on the v890's RSC card all purport to use the same pinout.
I use the same type of cables to connect my console server to v240's and v440's. Yet when I plug one of these cables into the v890 and tip, I don't get a connection. I did all the port and cable swapping you'd expect - cables that don't work on the v890 do work on a v440, and so on.
Using a different cable I can get to the DB25 at the back of the v890 with no problem. Normally this would be okay but I'd like to be able to remotely power on the boxes if I had to.
Using a laptop, Cisco cable and null modem adapter I can hyperterm into all three using the same configuration. This is what blows me away - if the 890's RSC card was truly different, this wouldn't work. But it does!
Does anyone have any ideas...?

Answer 1

Unfortunately a straight through cable won't work, and even rolled cables won't work. I had to figure out and then custom build my own cables. The RIM pinouts are:
1 RTS
2 DTR
3 TXD
4 DCD
5 RXD
6 GND
7 ---
8 CTS
...and the pinouts of the v240, v440 RSC, and (supposedly) the v890 RSC are:
1 RTS
2 DTR
3 TXD
4 GND
5 GND
6 RXD
7 DSR/DCD
8 CTS
So my cables from the RIM to the v240/v440/v890 look like:
1 RTS ----- 8 CTS
2 DTR ----- 7 DSR
3 TXD ----- 6 RXD
4 DCD ----- 2 DTR
5 RXD ----- 3 TXD
6 GND ----- 5 GND
7 --- ----- 4 GND
8 CTS ----- 1 RTS
The nice thing is that one end of this cable is a regular straight through connector, so really only one end has to be custom made. This type of cable is working fine for 25-30 other servers; the RSC cards on the 890 are the only problem I have right now.
Again, I've tried swapping cables - I unplug a working cable from a 440 and plug it into the 890; all of a sudden I can't connect. If I plug the non-working 890 cable into a 240 it will work fine.
I can hyperterm into the v890 RSC port with a rolled cable and a null modem adapter from a laptop. I use this same setup to connect to my 240's and 440's. This is maddening :(