Copy Error

Thanks to another great find by members over at Serve The Home forums, I picked up a couple of Baytech RPC-3 remote PDUs for dirt cheap.

Even though the Baytech Units are rated for 20Amps and come with a 20 amp plug, my home feed is only 15A so first order of business is to convert the 20 amp plug to a standard 15A one.

I picked up a couple of heavy duty plugs at Home Depot and went to work.

Simply cut off the existing plug and strip the individual wires

Then simply attach the wires to the new plug (make sure you get the Hot/Neutral/Ground right)

Reassemble the plug, all done.

Once both units were rewired it was time to configure them. One of the switches didn’t come with an IP address sticker and I tried unsuccessfully to discover the IP address manually. It was becoming apparent that I’d have to configure the switch via serial connection.

Unfortunately the baytech units use a non-standard DB9 to RJ-45 cable. Thankfully, Good Guy Baytech supplies the complete pinout in the manual so that you can make your own cable.

Note: The diagram assumes that this cable will be used with a Null Modem (rollover cable) and is pinned out as such

Making the cable is very straight forward. All that was needed was a short Cat-5e Patch cable, a female DB9 connector and some basic soldering skills. Simply cut the end of the patch cable, follow the pinout diagram and match up the wire colors in the opposite end of the cable to the proper DB9 pins. I ended up simply writing down the colors to pin matching so the soldering job went faster

Few minutes later I had a working Baytech cable.

Fortunately the console was not password protected so it was easy to change the admin password. If however the console was passworded here are the reset instructions for Baytech RPC3’s

1. Turn off the power to the RPC3
2. Remove the lid
3. Locate JP1 on the Ethernet board
4. The jumper is placed on pins 1 and 2, move it to 2 and 3
5. Turn power on for 10 seconds
6. Turn power off
7. Return jumper to its original position.

Once the IP address was configured via the serial console, the unit was ready for remote access

One last order of business before racking up the units was to provide a GUI driven interface for the unit. Since the RPC-3 uses basic command line telnet connection it was relatively easy to develop a basic app to control and monitor the unit remotely. Few hours of coding and I came up with a simple app that interfaces with the units.

The app can control individual outlets by right clicking on it, or many at once by selecting the check boxes and invoking an action.

Link to App: http://www.copyerror.com/shared/BaytechControl.zip

Now it’s just a matter of racking it up and plugging everything in.

The only complaint about these boxes is the master on-off button. I wish there would be some sort of cover over the switch as it’d be very easy to accidentally kill the entire pdu dropping all devices.

Manual: U140E125-05_rpc

Few months ago I used some RGB LED lighting in my room (eBay China special). The setup uses an IR remote control and a control box to control the lighting. Power is supplied via a high current 12V power supply (10A supply)

My “gaming” computer uses green LED fans which looks kind of odd when using any other color on the strip. Changing the color of the computer required swapping the fans for a different color.

So, I decided to modify the fans to sync the colors of the fans with the rest of lighting. I already had tons of RGB LED’s, so it was really a matter of A LOT of soldering. One thing to note is that the LED ligthing system uses common Anode configuration, with a single 12V rail and 3 (RGB) grounds.

Once I pulled the fans from the computer, I had to remove the old green LEDs from the fan.

Fortunately the LEDs are simply pressed into place and not glued. This makes them easy to pop out with just a little bit of force.

The leads for the fans are connected to a small circuit board underneath the sticker on the fan

A quick application of a soldering iron and all the LED leads have been removed. Since the LEDs are no longer supplied with fan voltage rail, the brightness of the LEDs will no longer be tied to the speed of the fans.

The RGB leds a just tiny bit larger than the original LEDs so it took a bit of extra force to press them into the socket.

I used standard ribbon cable to carry the RGB voltages across the LEDs in the fan. The individual current for each fan is very low so the ribbon cable can easily handle the load.

All LEDs were connected via point-to-point connections. This was actually a fair bit of work. The ribbon cable is quite delicate so I had to take extra care when stripping the wire ends as not to cut the lead.

The ribbon cable is nice and flat so it doesn’t affect the overall diameter of the fan much. Still, there would be certain configuration where the fans are too close to an edge where this would be problematic. Fortunately in my case, the fans are spaced sufficiently apart that the ribbon cable doesn’t interfere.

Once all the LEDs were electrically connected they had to be terminated via current limiting resistors. During bench testing I found that the 470ohm resistors provided the best brightness to current ratio at 12V. Since the LED receives power on a common Anode and each color draws slightly different amount of current, it’s important to place the resistors on the individual color leads. Putting the resistor on the anode pin will not work properly when using more than one color at a time.

With the first fan completed I did some testing to see how the setup will stack up. I wasn’t sure if the RGB LEDs will be bright enough.

At 12V the individual colors only draw about 30mA per fan.

With all the colors lit, the draw was just 90mA. Which works out to under 500mA for the whole computer. A negligible load on the control box for the ambient lighting.

To connect the fans to the LED strip I bought some JST 4 pin connectors. It’s surprisingly difficult to find small 4 pin connectors locally, so I had to do another China eBay order and wait another month for them to show up.

To complete the connection, all the resistors were then wrapped via heatshrink and soldered to the connectors. I gave each fan about 8″ of wire to make the connections between the fans easy.

To connect all the fans together and to connect them to the LED strip I braided few 24 gauge wires to make a nice flat cable. This cable will run outside of the computer via a hole (meant for water cooling hose) in the computer case.

Once all the fans were soldered up, I installed them back into the computer. My wire organization skills are certainly not the best, but then again this is just a Mini ATX case so not heck a lot of room to stash the cabling.

Last step was to connect the supply cable to the LED strip and turn it all on.

Here’s a short video of the LED system, with the light mode set to cycle all colors.

I did another border run recently to pick up some more eBay goodies.

Over the last month or so I scored some incredible deals on server hardware. Picked up a couple of Intel SR1680MV Dual node servers, my favorite in 1U config right now. A really cheap HP Storageworks MSA70 with 25 Trays and some other items.

Also picked up a pair of Minuteman Remote Power Management switches. These babies use to sell for over $800 a piece, I picked them up for about $20 each. Now granted these are most likely VERY old devices. I’ve never heard of Minuteman but for that price I was very much willing to give them a shot.

Each switch can manage 8 power ports. Each port can be designated for remote operation (via HTTP, Telnet or SNMP) or local only.

The switches come with 8 power ports each rated for a total of 12A @ 120V. Unfortunately the switches do not report actual power draw at port or total. Each power port comes with it’s own RJ11 port that can be use to interface with a respective UPS or Computer, a feature I’ll most likely never use.

The switches were both “supposed” to come with a management card but the seller screwed up and sent me only one. Since I already considered this a pretty good deal I didn’t want to send them back even though the seller offered a full refund.

The lack of a second management module isn’t a big deal since these devices can be chained and managed from a single card, but more on that later.

First order of business is to try to log into the thing. Unfortunately the devices came with no instructions or passwords of any kind. So, I connected the switch to my lab network and checked to see if by any chance the device is set for DHCP. No luck, DHCP lease list didn’t show any new devices on the network. A quick search for a manual on the Minuteman site and I came across SNMP based discovery snmp32_utility.

Once again ran into a small issue as the software doesn’t seem to work under Windows 7 and up (network list is empty).

Fortunately I have an old toughbook kicking around that has Windows XP 32 bit installed. A quick install and bingo! the device shows up. Attempting to access the device resulted in a password prompt. Once again I lucked out since the password was simply set to “admin” and it only took me 3 tries to figure it out.

I cleared the password and set the device for DHCP.

Once web access got enabled I fired up my browser and pointed it at the device IP. Crap! Another password prompt. This time no amount of defaults was able to bypass this login screen.

Fortunately, through a lot of web searching I found a procedure to factory reset the management card which clears any passwords on it. The process is as follows

* Remove the screws holding the management card in place
* Using a small tool press the "Reset" button on the management card and hold
* While holding the reset button pull the management card out of the switch unit
* Continue holding the reset button, wait a few second then re-insert the card to power it up.
* Continue holding the reset button for another 40 seconds and release.
The management card has been fully reset.

Once the card resets, reconfigure the card for DHCP again and use blank login/password on the site credentials and *boom* we’re in.

Now that we have access to the card, time to figure out how to chain the two. Based on the manual for the device. The switch comes with an “iLink” cable and a terminator plug. I received no cable and only one plug.

I picked up a 6 lane RJ11 cable and plugged it into the boxes as described by the manual. However, no matter how I placed the cable and the one terminator plug, the device would never see the second box.

My first assumption was that I need a second terminator plug to close the loop. Since I only had one I decided to figure out how it works and build another one. I was pretty sure that due to the small size of the plug only passive circuitry is used inside. A quick run-through with a multi meter confirmed my theory and I determined the internal connections in the plug.

The pins on the terminator plug are simply connected via 1K and 5K resistors.

All I had to do was build a similar plug. I quickly whipped up a ghetto plug for testing and confirmed that it works since the master switch behaves slightly differently with it plugged in.

Once again ran into a roadblock. The addition of the second terminator did not result in connectivity between the two switches. Upon closer inspection of the cable I realized that the wires in the cable are not straight-through but rather reversed.

I snipped the cable, reversed the wires and put another RJ11 plug on it and EUREKA! Both switches are accessible via the management interface. It also turns out that the terminators seem to be unnecessary in this configuration as the switches had no problem operating with the terminators removed.

I will probably toss these into one of my data centers where I’ll be able to reboot machines without having to drive for over an hour.

Files for this product:
snmp32_utility
SNMP-32-SL_manual
RPM_manual