Building the cable and preparing to test the SDLC link from 3174 to Hercules via SDLC

CHECKING MY SDLC VERSION OF THE 3174 CONTROL DISKETTE 

I did an IML of the controller with the new Control diskette configured for SDLC, using the EIA cable with the switches set to TEST for wrap of the RS232 signals. It did boot up giving me two status messages. 

Initially it reported 501 status with a sub status of 0111. This says that SDLC is waiting for a host (mainframe) to connect to it. After a short while, I got the 532 on the operator panel and on the status line of the terminal, with a sub status of 0311. This is a timeout of the SDLC link to the remote end, appropriate because we have a wrap of signals and not an actual device on the far end of the cable.

BUILDING THE CABLE

I took the loop cable I bought, which has Smart Serial plugs on both end, one wired as DTE and the other as DCE, then cut it in the middle. I now have a DCE and a DTE cable with individual wires at the other ends. The connectors are internally wired to define the type of serial protocol and whether it is DTE or DCE, so I just had to select the correct side. 

The Smart Serial cables tell the Cisco router the type of connection they are making by grounding certain pins, the pattern encoding which kind of serial connection and whether this is acting as DTE or DCE. In my case, pins 22 and 23 were connected to pin 26 in the cable, thus asserting this as an EIA DCE link. 

Beeping out the wires gave me the wire color of each active pin from the Smart Serial end - then I soldered it to the DB25 pin that corresponds to that signal. The result is the same as the Cisco cable CAB-SS-232FC which provides EIA (RS232) as DCE to connect to the cable from the 3174 which is EIA DTE. 

Test cable based on diagrams

I did some verification testing of the connector wiring and found a non-obvious short. There appeared to be an air gap between the adjacent pins but the multimeter insisted that electrons flowed between them. I took a picture and zoomed in closely, where I observed some wire whiskers that formed a wee jumper between the pins. Each enough to cut away so the connector wiring is correct. 

Cross jumper formed by wire whiskers

CHALLENGES GETTING THE 2811 ROUTER CONFIGURED AND CONTROLLABLE

The eBay seller from whom I bought my 2811 router provides a CF card with all the key configurations and software needed by students working on their Cisco networking certifications, however they failed to clear the nonvolatile ram image before sending the box to me.

This means that the box was still configured for its role doing IP telephony at a bank, along with all the passwords still set but not disclosed to me. I have no experience doing Cisco administration nor using the command line interface to manage such a box, but had to learn quickly. 

I figured out how to bypass the passwords then replace them all - after five or six partial attempts that still left the box unable to be fully managed.  I turned off a number of functions that had been used by the prior owner before setting up the DLSw and Serial interface settings.