johnk@opel.uu.net (John Kennedy) (10/02/89)
Got a Telebit Trailblazer+, and two phone lines serving two dialing
areas. I'm trying to come up with a scheme that allows me to
dial out on either of the two lines.
I'm assuming that I'll use some sort of solid state relay, or
even a telephone crosspoint chip, but don't know yet how I'll
control it.
So far, the options I'm considering are:
1) A device driver in the host system that will toggle a lead.
This would be actuated just prior to sending the dialing
sequence to the modem, and reset at the end of the call.
2) A UART and controller which listens to the AT sequence being
sent to the modem, and which switches lines upon detection
of a certain AT sequence.
3) A DTMF decoder which listens to an outpulsed sequence from the modem,
then connects one of the two lines in time for the delayed, real
digits.
4) If I replaced the modem with a Telebit T2000, the option exists
to assert the A/A1 leads (second pair) coming out of the modem.
Techs at Telebit confirmed that the TB+ does not have this capability.
These leads could be used to control the switching. Anyone
using these?
Option 1 would require the least hardware, but I have a concern about
leaving the wrong line connected in case of an aborted dialing attempt.
Anyone done anything similar, or have any suggestions?
Thanks in advance,
John
--
John Kennedy johnk@opel.uu.uunet
Second Source, Inc.
Annapolis, MDtcm@srhqla.SR.COM (Tim Meighan) (10/05/89)
In article <282@opel.uu.net> johnk@opel.UUCP (John Kennedy) writes: >Got a Telebit Trailblazer+, and two phone lines serving two dialing >areas. I'm trying to come up with a scheme that allows me to >dial out on either of the two lines. If you aren't using DSR (or other RS-232 handshake line) out of the modem, and it can be asserted/de-asserted via register settings, just let that control a DPDT relay that toggles you between the two phone loops. Then, you can select which one you want right in your dial sequence. To interface, you can just have it raise the base lead of an NPN transistor, which in turn controls the relay through an external power source. You'll want a diode and resistor in series in the control line to limit current, provide isolation, and keep the -12 volts from appearing at the transistor. Don't forget a diode wired "backwards" across the relay coil leads to keep EMF spikes from destroying the transistor when the relay turns on and off. While you could probably find a very low-current relay that would pull-in directly off the current of the handshake line, it's not really the right way to go. These lines are signal lines, have limited current available, and are not intended to be used as drivers. Tim Meighan SilentRadio "Hit ENTER to exit."
wiz@xroads.UUCP (Mike Carter) (10/05/89)
Use a real operating system. If you want to dial out on either line and you need hardware to do it, then there's something wrong with your choice of O.S. I'm running QNX (Que-Nix) on a 286 with two phone lines. I can call in on one, and then tell the computer to dial a number out and connect me through the two. (A complete waste of lines, but I've done it many times.) You need to get a true multiuser, multi-tasking O.S. -Mike -- ============================================================================= = Mike Carter N7GYX, Phoenix AZ| Q: Why did the Chicken cross the road ? = = hplabs!hp-sdd!crash!xroads!wiz| A: To ESCape the Main Menu . = =============================================================================
wcf@psuhcx.psu.edu (Bill Fenner) (10/06/89)
In article <846@xroads.UUCP> wiz@xroads.UUCP (Mike Carter) writes: | |Use a real operating system. If you want to dial out on either line |and you need hardware to do it, then there's something wrong with your |choice of O.S. An OS flame is quite inappropriate, especially since you seem to have missed the point. |I'm running QNX (Que-Nix) on a 286 with two phone lines. |I can call in on one, and then tell the computer to dial a number out |and connect me through the two. (A complete waste of lines, but I've done |it many times.) The original question was how to switch *one* modem between *two* phone lines. If your solution is for him to buy another $1500 modem, I'm sure he'd be glad to have you pay the bill. In the future, please *read* before you flame. Bill -- Bitnet: wcf@psuhcx.bitnet Bill Fenner | aaaaaaaaa Internet: wcf@hcx.psu.edu | r UUCP: {gatech,rutgers}!psuvax1!psuhcx!wcf | g Fido: Sysop at 1:129/87 (814/238 9633) \hogbbs!wcf | h
johnk@opel.uu.net (John Kennedy) (10/06/89)
In article <846@xroads.UUCP> wiz@xroads.UUCP (Mike Carter) writes:
-
-Use a real operating system. If you want to dial out on either line
-and you need hardware to do it, then there's something wrong with your
-choice of O.S.
-I'm running QNX (Que-Nix) on a 286 with two phone lines.
-I can call in on one, and then tell the computer to dial a number out
-and connect me through the two. (A complete waste of lines, but I've done
-it many times.)
-You need to get a true multiuser, multi-tasking O.S.
OK, I'll bite. I'm running (real) UNIX on a 286. The high dollar
modem is connected to /dev/tty2. Two of the computer's phone lines
go to either of two dialing areas.
Now, when the outgoing call is initiated, I want to choose which line
will be used by the modem on /dev/tty2. Please continue.
John
--
John Kennedy johnk@opel.uu.uunet
Second Source, Inc.
Annapolis, MDwb8foz@ibiza.cs.miami.edu (David Lesher) (10/08/89)
> Article <846@xroads.UUCP> From: wiz@xroads.UUCP (Mike Carter)
[Some pointless flame, that clearly indicated that the wiz
needs lessons on reading, as well as manners, deleted]
Strange we have not heard from this expert again...
maybe he's busy writing software to switch phone lines...
--
A host is a host & from coast to coast...wb8foz@mthvax.cs.miami.edu
no one will talk to a host that's close..............(305) 255-RTFM
Unless the host (that isn't close)......................pob 570-335
is busy, hung or dead....................................33257-0335Keith.Dickinson@p0.f2202.n124.z1.FIDONET.ORG (Keith Dickinson) (10/08/89)
In an article of <5 Oct 89 00:37:40 GMT>, wiz@xroads.UUCP (Mike Carter) writes: >Use a real operating system. If you want to dial out on either line >and you need hardware to do it, then there's something wrong with your >choice of O.S. >I'm running QNX (Que-Nix) on a 286 with two phone lines. >I can call in on one, and then tell the computer to dial a number out >and connect me through the two. (A complete waste of lines, but I've done >it many times.) >You need to get a true multiuser, multi-tasking O.S. Maybe he's like me and doesn't want to shell out the money for a second TB. I've run Unix and have found that no matter how hard you try, you can only dial out on one phone line when you've only got one modem. Keith -- Internet: Keith.Dickinson@p0.f2202.n124.z1.FIDONET.ORG UUCP: ...!attctc!tlsi!2202.0!Keith.Dickinson Disclamer: My news handler is unstable. If you see a message that you believe couldn't have originated here, please inform me so that I can better track down the problem. Thank you - nanook@tlsi.fidonet.org
akcs.larry@nstar.UUCP (10/09/89)
Someone mentioned QNX as a option supporting multiple lines. Funny one should mention QNX - as it is not compatible with anything - and the CI ANSI compiler is a bag of worms. Quantum's answer to everything is "it is in the works" or "next quarter". QNX is a dead end street..
akcs.larry@nstar.UUCP (10/09/89)
> >I'm running QNX (Que-Nix) on a 286 with two phone lines. Too bad. QNX is a dead end street with no support from any of the major softwar vendors - it took them 7 years to finally get Enable ported. >I've run Unix and have found that no matter how hard you try, you can only >dial >out on one phone line when you've only got one modem. That's the bottom line. I have called in from the office using V.32 - to V.32 (on this box running SystemV) then out the TB port using ProYam. No biggie.
mrm@sceard.Sceard.COM (M.R.Murphy) (10/10/89)
In article <[25308f69:15.1]comp.dcom.modems;1@nstar.UUCP> akcs.larry@nstar.UUCP writes: >> >I'm running QNX (Que-Nix) on a 286 with two phone lines. > >Too bad. QNX is a dead end street with no support from any of the >major softwar vendors - it took them 7 years to finally get Enable ported. > >>I've run Unix and have found that no matter how hard you try, you can only >>dial >>out on one phone line when you've only got one modem. > >That's the bottom line. I have called in from the office using V.32 - to >V.32 (on this box running SystemV) then out the TB port using ProYam. No >biggie. QNX(tm), UNIX(tm), MSDOS(tm). Makes no difference to the stated problem. If you can trot down to your local Radio Shack(tm) and buy a DPDT(not tm) relay and hook it up to two telco lines and your modem, and if you can either drive it off one of the spare control lines on an existing board (without a driver if you have a relay that doesn't take much poop to drive, or with a transistor(too bad it wasn't tm:-) if it does), or beg, buy, or steal another interface board and use a signal from it, then you can use one modem with two phone lines for dialout if you can beg, buy, or write the software to flip the signal and switch the relay. If you can't, then the problem becomes harder. You could use two lines with one modem for dialin, too, by switching the relay every few seconds under software control while waiting for RING or CD or whatever you like. When the signal shows, connect away. Then the other line can't be answered until the first call completes, but you did want to avoid the purchase of a second modem, didn't you? The solution can be as elegant or Rube Goldbergish as one wishes. Digital switches come to mind, but it seems like an overkill. Send SASE(also not tm) for circuit diagram and instructions:-) -- Mike Murphy Sceard Systems, Inc. 544 South Pacific St. San Marcos, CA 92069 mrm@Sceard.COM {hp-sdd,nosc,ucsd,uunet}!sceard!mrm +1 619 471 0655
macy@fmsystm.UUCP (Macy Hallock) (10/14/89)
In article <1890.252E9E05@tlsi.FIDONET.ORG> Keith.Dickinson@p0.f2202.n124.z1.FIDONET.ORG (Keith Dickinson) writes: >In an article of <5 Oct 89 00:37:40 GMT>, wiz@xroads.UUCP (Mike Carter) writes: > >I'm running QNX (Que-Nix) on a 286 with two phone lines. > >I can call in on one, and then tell the computer to dial a number out > >and connect me through the two. (A complete waste of lines, but I've done > >it many times.) > >Maybe he's like me and doesn't want to shell out the money for a second TB. > Well, here's an off the shelf solution from a telephone man... Panasonic makes a small telephone system (generally used for small businesses) that will act as a small PBX with modems very well. The KXT308 system is set up for 3 "outside" lines and 8 "extentions" and loves modems and faxes, etc My company sell and install these things for business. We love 'em. Our customers love 'em. You just might, too. You will need: 1 ea. Panasonic KXT30810 Key Service Unit and 1 ea. KXT30830 LCD Display Telephone (the phone is used for programming) The systems uses regular RJ11C type phone jacks throughout. The instruction manual is OK, and Panasonic gives a toll free assistance no. in the manual (which is often busy) You will program the modem to dial 81(pause)+no. for line one, 82 for line two and 83+ for line 3. Incoming ringing is programmed to your desires by you. You cannot use this systems as a smart fax switch or automated attendant without extra equipment (but it can be done). For the best price: Try the New York discounters. Be sure they have it in stock (many do not stock this item, they can't figure out what it is) IMHO- This system belongs in every home and office with two or three lines and modems/faxes. Panasonic makes a six line, sixteen station version called a KXT616, too. This is just a larger version of the 308. They also make a twelve line, thrity-two station version, but it is complicated and not for the faint of heart (telecom-wise, that is). These systems will work behind Centrex or PBX's that are touch-tone or rotary-dial, as long as they use a standard two wire 2500 set type instrument, just like any modem requires. I can answer more specific questions on a time permitting basis. If you are really serious, let me know, I can give you a great deal of info and help, but be prepared to pay for it. (Thats how I pay MY rent...) Regards, Macy Hallock fmsystm!macy@NCoast.ORG F M Systems, Inc. hal!ncoast!fmsystm!macy 150 Highland Dr. uunet!hal.cwru.edu!ncoast!fmsystm!macy Medina, OH 44256 Voice: 216-723-3000 X251 Disclaimer: My advice is worth what you paid for it. Alt.disclaimer: Your milage may vary. Biz.disclaimer: My opinions are my own. What do I know?