Serial ports of rx2600 / rp3440

[Torsten.]

What do you want to do now? Running a getty on the UPS port?

Is there any special software for the UPS?
Normally such software is either autodetecting the device on a given port or needs the port and speed only (speed depends on the device).

[Martin Vorlaender]

> What do you want to do now? Running a getty on the UPS port?

That could be an option. For now, just setting up the port and cat'ting a text file so that it comes out okay would be nice.

> Is there any special software for the UPS?

Probably. I'll tell him about the port to use; then he can check whether it works with his UPS.

Thanks.

[Bill Hassell]

>> Is there any special software for the UPS?

> Probably. I'll tell him about the port to use; then he can check whether it works with his UPS.

Actually, I would ber very surprised that there is anything compatible with HP-UX. The vast majority of small to medium UPS units are PC-only, with an occasional unit that offers some Linux code.

Note that if you cannot use stty to read the current settings from a serial port then the port is non-functional -- no need to try to get it to work. Note also that the default setting for a serial port is 300 baud, but you will see this with stty -a < /dev/tty1p<1,2 or 4>. Using stty ro set the baud rate will not stick -- you must first open the port with something like: sleep 10000 < dev/tty1p2 and then use stty. For a permanent solution, you'll need to create a script with a lot of specialized code, especially if you want this UPS to perform an orderly shutdown is case of an extended powerfail.

[TTr]

Setting up a serial port with getty and configuring a UPS are two different things when it comes to serial port setup. As Torsten hinted, the UPS software (if it exists) takes care of the serial port communication, all you need to do is give it the serial port device. Take a look at this thread for some more insight into a UPS setup. http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1353252

[Martin Vorlaender]

Bill,

actually, I think the customer had some software working with an rp5430 under HP-UX 11.11 (I haven't seen any of his machines - yet). But that wasn't his (primary) problem; it was that he (and me, too) couldn't find any documentation WRT the multiplexed serial ports.

Thanks for the *IX stty/serial 101.

cu,
Martin

[Martin Vorlaender]

TTr,

thanks for the link. However, I think the r5500 and the MGE (now Eaton) Evolution work quite differently when it comes to the serial communication.

cu,
Martin

[Bill Hassell]

> I tried multiple things, setting the speed to 9600 and 19200, and even to 300 (as that is what stty tells me when queried about /dev/tty1p[24] )

Sorry I missed this note. So the p2 and p4 ports are functional. Whatever you are using tyo see if the port is working will require a special cable. As is true with virtually all computers with serial ports (PCs haven't had any for years), there are two completely incompatible serial cables: straight through (also known as a modem cable) and crossover (aka, printer or null modem) cable. For any serial connection troubleshooting, you will need both cables or at least a straight through plus a null modem adapter.

Virtually all HP-UX computers will need a crossover cable. Connect a real terminal or a PC running any terminal emulator. Set the terminal to 300 baud and cat a file to the port:

cat /etc/profile > /dev/tty1p2

If this doesn produce any data on ther screen, try the straight through cable.

Once you have the port working at 300 baud, you can try running the UPS software. Note that serial port UPS boxes have a colorful history of using non-standard connector pinouts. You'll need to get the tech ref manual for the UPS from the manufacturer to verify your cable will work. Most UPS boxes have no way to let you know that the connection is not complete. Such things as DTR, CTS, RTS signals will prevent the UPS from listening or replying if they aren't set correctly.

"Simple serial connection" has always been an oxymoron. That's why so many serial analyzers and pin monitors have been sold over the years. Even the HP DB25 connector is completely non-standard (3 ports on one connector?). Here is a summary of the RS-232c standard:

http://en.wikipedia.org/wiki/RS-232

[Martin Vorlaender]

Bill,

believe me, I have seen ALL of the serial muddle over the years (though not with HP-UX, but with VMS at the end of the line).

The serial port of the MGE Evolution seems to really only be a DB-9 plug with some pins signalling the state of the UPS - something VERY special... But this is just an assumption on my part, as I don't know whether I'm loooking at the right documentation.

For now, thank you all very much. You've been very helpful

cu,
Martin