PCI MUX to Modem cable on an N4000

[Ken Cook]

I am trying to move a modem from my K460 MUX to a new N4000 with a 16 port RS232 pci_mux on it. (J2485-60010) The problem I am having is that I can dial out, but I am not getting the callback. I am wondering what type of cable I should be using between the modem and the mux?

[Sandip Ghosh]

If it work for dial out with the same cable then dial in should also take place. I think you have to do something on OS side.

Have you created the getty for your modem line and made it respawn in /etc/inittab file? do a ps -aef and see if the getyy is running on that port?

Sandip

[Ken Cook]

Unfortunatly for me, the application group has a home-grown application that opens the modem and waits for a callback, so no getty's are setup. So it is not a standard modem install.

[MANOJ SRIVASTAVA · Accepted solution]

Hi Ken


The same cable should work fine , however for you inforamtion the pins should be as :

2-------------2
3-------------3
7-------------7
4-------------4
5-------------5
6-------------6
20------------20

or use a normal PC to MOdem Cable the one which has both 25 and 9 Pins (striaght through cable ). I think you may also look at the modem dip switched ( in case it is set up for lease line or auto answers stuff ) . You can dial the line to the modem and look for the rsponse like ehwter it is ringing and after how many rings it answers , also on the /etc/inittab is that line switched off or respawning .

Manoj Srivastava

[Jeff Schussele]

Hi Ken,

I suspect that if the device is being controlled by the app & I assume the app is doing the dialing out - then it should probably reset the modem (ATZ if Hayes compatible) or send the auto-answer string after dialing to ensure the modem will answer. I bet the modem is "hung" after the dial-out.
Try dialing the modem immediately after the dial-out & no callback scenario to see if it will answer.

Rgds,
Jeff