Question IBM LCM8 / 1754-HC3 - Serial Cable?

ember1205

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Hi, all.

I bought a server rack and an IBM KVM about 5-6 years ago, used. Everything works great but I want to set up Console Access to the switch. I'm not having any luck getting the computer to actually communicate using a Cisco rollover cable and I'm wondering if anyone has any details on what the cabling / pinout requirements are for this specific port access.

I have tried a known-good Cisco rollover cable and a straight through ethernet cable (non-crossover wired) and both yield nothing but a flashing cursor.

If any knows any details here and can help, it would be appreciated. Thanks!
 

USAFRet

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Changing the text slightly does not get around the original question you asked.

Closing this one as well.
 

ex_bubblehead

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Changing the text slightly does not get around the original question you asked.

Closing this one as well.
I've been in contact with the OP and have OK'd this repost. I'll post the details in the Mod threads.
 

ember1205

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You'll find the manual here: https://www.ibm.com/support/pages/installation-and-users-guide-ibm-local-console-manager-lcm8-and-lcm16-1754

From your description you're either connecting to the wrong port with the wrong cable or using the wrong serial configuration (most ports are 9600 8 N 1)
Thanks. While that manual does have a little bit of information, it's still somewhat vague on the details and that's why I'm here - the overall process for things like setting communications variables and executing firmware updates lacks technical details for actually cabling things up. The one doc that mention using a "DB9 Female to DB9 Male serial cable" also lacks any details as to whether it's a rollover (null modem), straight through, or crossover (like an ethernet cable) connection (or something entirely different).

There is a firmware update document (as mentioned above) that discusses specifically NOT using a USB to serial adapter as your connection method. So, when that method simply wasn't working, I tried using linux / unix "screen" program against /dev/ttyS0 on a host that is old enough to actually have a real serial port and that didn't work either. At one point, I was getting what looked like -some- sort of communication on the USB adapter (flashing lights) even though I saw just the flashing cursor on the screen.
 

ex_bubblehead

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ember1205

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https://systemx.lenovofiles.com/help/topic/com.lenovo.sysx.racks.doc/rk_lcm_iug_v1_en.pdf

Pinouts and configuration are in Appendix 2. Appendix 1 covers terminal setup. You must use a terminal program such as Telix, PuTTY or KiTTY setup in accordance with the instructions in Appendix 1. The PC side of the cable is standard 25 or 9 pin serial (a real serial interface NOT USB-to-serial). And yes, you must cross over TX/RX.
Interesting info - thank you. While it does use the LCM8/LCM16 naming, it doesn't seem to mention the specific model I have (1754-HC3). Still, the pictures appear accurate and it does reference the correct types of connectors (the other manual refers to using a DB9 connection on the switch itself which is wrong).

Moreso, I expect that the port pinouts will be the same across different platforms, and that would seem to indicate that I need to connect pins 2 & 3 on the DB9 port to pins 4 & 5 on the RJ-45 port. Looks like I'll be pulling out the CAT5, the connectors, and the crimp tool. This is likely the piece I was missing / had wrong. I should get a chance to test this out later this week and can report back whether I can get more than just the cursor to flash. :)

As far as the terminal program, I am going to start by validating 'screen' against my Cisco switch console port. As long as that works correctly, I see no reason I can't use the exact same hardware / software setup to manage the KVM once I change to the correct cable.
 

ember1205

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OK... I finally got this squared away after a fair amount of trial and error...

There are THREE aspects to building the correct cable - The DB-9 connector, the DB-9 / RJ-45 Adapter, and the RJ-45 connection on the KVM device. Pins 2 & 3 on the DB-9 connector carry Tx/Rx while pins 4 & 5 at the console do the same. The wildcard is the adapter and that throws a fair amount of weirdness into the mix because it has its own map of pins.

In the end, I cut an RJ-45 cable in half. On the DB-9 end of the connection I used the White'Green (Pin 3) and Green (Pin 2) wires (568B wiring standard) and crossed them to the Blue (Pin 4) and White/Blue (Pin 5) wires on the console end.

I was able to get proper communications off of a Linux host using the command:

screen /dev/ttyS0 9600,cs8,-parenb,-cstopb,-hupcl


I also tested the setup on a different linux host that doesn't have an actual serial port and I used a USB/Serial adapter. Same connections, same screen command (using /dev/ttyUSB0), and it works fine as well.

I have been able to validate various settings and can connect to the web interface. But, the software requires java in your browser to actually launch console sessions, so on to my next challenge with this! lol
 

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