About MODEM and HP-UX

[Thanasis_3]

Hello,

I want to install a modem on the an HP-UX server in order to connect remotely.

I'd like you to suggest me some types of modems which are about to work for sure.

P.S. I want to use the "UPS" serial port of the server.


Thank you in advance

[Rajeev Shukla · Accepted solution]

Infact all modems will work on HP Server.
COnfigure them using SAM and in some modems you might have to enable CCITT(european standard) and in some you may not. Also dont enable hardware flow control.

I have tried Hayes, Robotics and Netcom Modem they all definately work.

Cheers
Rajeev

[Alexander M. Ermes]

Hi there.
Just a hint.
MutliTech modems are supported by HP.
The others are not.
I would get a MultiTech.
In case of problems with the config you may call HP support.
Rgds
Alexander M. Ermes
BTW
We use these to dial in and out for more than eight years now.

[Thanasis_3]

Well.. I have already a multitech modem 19200 but it doesn't work. In fact it doesn't answer any call! I have used the ats0=1 command (in order to answer after 1 ring) but nothing happened. So I decide to search for another modem.

Any AT configuration (for any modem) would be appreciable..

Thank you

[Rajeev Shukla]

Hi,
I bet you use Netcom or hayes modem they work perfectly allright, i wonder if you are using right cable connection coz HP recomends a different cable connection. Search on the ITRC for cable connection you'll get it.
Also ensure that you have selected "receive incoming calls" and getty is running on the port configured for modem.
Surely the modem will answer if all above is meet.

Cheers
rajeev

[Darren Prior]

Hi,

If this the same server you mentioned in your other thread about serial printers, I'd suggest you use a spare mux port for the modem. The document I mentioned in that thread also shows pinouts for modem cables. If you wish to buy a cable to use between the RJ45-DB25 adaptor then the HP part number is 40233A.

On some HP servers the UPS port doesn't have all the necessary handshaking lines for modem use.

regards,

Darren.

[Karamanolis Nikos]

Thanasi,

If it does not answer calls, try toggling the DTR behaviour of the modem. (Suppose that inittabs nad gettys are ok and running)...

And also turn off modem-port flowcontrol.

Think on a multitech the ATs are &D0 &K0.

Hope it helps...

Kalimera...

[Thanasis_3]

Yeah, it's about the same server I was talking about.
Even If disconnect the modem from everywhere (except power :)) ) and have only a telephone line on it ...it doesn't answer the calls!
So, if I use the "UPS" port can I use the standard cable which is provided for the PCs?
Or it's better to use a MUX port?
I don't have the time to search for specific cables or to make spesific cables.

I'm confused guys!!! :)

[Darren Prior]

Hi,

Your comment about the modem not answering if it's disconnected from the server is fine. The modem should be set up so that it only answer the line if DTR is present. This is a signal sent by the server when a getty is running on the port.

As for the UPS port vs mux port; well I would always advise to use the mux port. The mux ports have all the handshaking necessary for modems, whilst the UPS port may not. It's possible that a modem on the UPS port would answer the line once, then you may have to powercycle the server - which is not a good way to work!

regards,

Darren.

[Thanasis_3]

Ok..
So, If i'm gonna use the Mux port with a Multitech 19200 modem, which are the steps I have to follow? (type of cable, AT commands etc.)

[Darren Prior]

Hi,

Hmmm, steps. Well firstly use the cable mentioned earlier with your converter, or make your own using the pinouts listed in the document referenced in your other thread.

You'll then need to add the modem using SAM, make sure you tick the box for incoming alls, but don't tick the CCITT box (unless you know that you need it.) This will create the necessary device files and an entry in inittab for a getty.

Next, you'll need to send a modem-specific string to configure the modem. If you let me know the exact model of MT 19200 modem you have I'll see if I have a string for it.

regards,

Darren.

[Thanasis_3]

It's a Multitech MT1932 ZDX modem.

How can I send the AT commands to the modem while it is conected to the server?

Thank you!

[Darren Prior]

Hi,

You'll need to use Kermit or cu to send the string. Type kermit, and you'll get to a C-Kermit prompt. Then type the following lines:

set line /dev/tty
set speed 19200
connect
at

The modem should respond with an OK. Now type in the full string below. The modem should respond with an OK. You can then use Ctrl-\ C to get back to the prompt and use exit to quit from Kermit.

The closest I have to your modem is the 2834ZDX. You'll want to check the various parts against your manual to ensure that they're the same.

Here's the string split into parts that you can look up:
&F reset to factory defaults
&D3 reset modem when DTR dropped
&E7 XON/XOFF modem responds/pass through (only if &E5 is set)
&E5 XON/XOFF flow control
Q2 Enable no-response answer mode
&Q1 AT responses
$SBxxxx serial port speed (server <-> modem)
&W0 store settings in non-volatile RAM, use these settings when powered up or reset

Here's the whole string:
AT&F&D3&E7&E5Q2&Q1$SB19200&W0

regards,

Darren.

[Thanasis_3]

Well... After 30 minutes I made a 40233A adaptor with this configuration:

40233A
9000/800 Series Modem cable
CPU Modem
-------------------------------------------
Gnd 1 ---------- 1 Gnd
RD 2 <--------- 3 TD
TD 3 ---------> 2 RD
RTS 4 <--------- 8 DCD
DSR 6 ---------> 20 DTR
GND 7 <--------> 7 GND
DCD 8 ---------> 4 RTS
9 <--------- 22 RI
DTR 20 <--------- 6 DSR
RI 22 <--------- 5 CTS

(is this configuration right??)

I can't test it right now, so I have to wait until friday.
Thanks for the help!

[Darren Prior]

Yes, that's the correct pinout for the cable. Be sure to connect the right side to your modem, the left to the mux (via the converter.)

regards,

Darren.