dittman@skbat.csc.ti.com (Eric Dittman) (11/27/90)
[I've figured out that this post didn't make it out earlier, so here is my
request for help again.]
I'm trying to use hardware handshaking between my Mac IIfx and an ATI 2400etc/e
modem. My cable is wired:
DIN-8 DB25
--------------------
1 20
2 8
3 2
4 7
5 3
6 N/C
7 N/C
8 7
I've been told this is correct. I'm using Smartcom II. If I turn hardware
handshaking on with SC II and configure the modem using AT&K3 (or AT&F2 which
sets the modem up for V.42 operation) I can talk to the modem with no problems.
After I call a remote system and the modem goes on-line, though, I don't get
anything from the remote system, and the remote system doesn't get anything
from my system. Sending '+++' gets the modem back into command mode, though.
Any ideas what I'm doing wrong?
Thanks,
Eric Dittman
Texas Instruments - Component Test Facility
dittman@skitzo.csc.ti.com
dittman@skbat.csc.ti.com
Disclaimer: I don't speak for Texas Instruments or the Component Test
Facility. I don't even speak for myself.jack@Taffy.rice.edu (Jack W. Howarth) (11/28/90)
In article <1990Nov26.183217.236@skbat.csc.ti.com> dittman@skbat.csc.ti.com (Eric Dittman) writes: >[I've figured out that this post didn't make it out earlier, so here is my > request for help again.] > >I'm trying to use hardware handshaking between my Mac IIfx and an ATI 2400etc/e >modem. My cable is wired: > >DIN-8 DB25 >-------------------- >1 20 >2 8 >3 2 >4 7 >5 3 >6 N/C >7 N/C >8 7 > >I've been told this is correct. I'm using Smartcom II. If I turn hardware >handshaking on with SC II and configure the modem using AT&K3 (or AT&F2 which >sets the modem up for V.42 operation) I can talk to the modem with no problems. >After I call a remote system and the modem goes on-line, though, I don't get >anything from the remote system, and the remote system doesn't get anything >from my system. Sending '+++' gets the modem back into command mode, though. >Any ideas what I'm doing wrong? > >Thanks, >Eric Dittman >Texas Instruments - Component Test Facility >dittman@skitzo.csc.ti.com >dittman@skbat.csc.ti.com > >Disclaimer: I don't speak for Texas Instruments or the Component Test > Facility. I don't even speak for myself. The best way to use hardware handshaking on a modem is to set the modem to CPU connect rate at 9600 baud or 19200 baud and use the following settings AT\J0\V1\N3\Q3 or equivalents for your command set. J0 turns off the autobaud rate adjust between the modem and the CPU. V1 gives verbose messages which are good as you'll get info about whether the connection is using MNP. N3 sets hardware handshaking for flow control and Q3 sets error checking on. This setup with hardware handshaking will connect with MNP if possible and at the highest baud rate possible. If MNP5 or v42bis is used, the higher baud rate between the modem and CPU prevents that from bottlenecking the transfers (i.e. a MNP5 connection at 2400 baud with 9600 baud between modem and CPU.) Cheers... Jack Howarth
lriggins@blackbird.afit.af.mil (L. Maurice Riggins) (11/28/90)
Here's how your cable should pin out for each
of the types of handshaking:
Mac Xon/Xoff Hardware
Mini- Handshake Handshake
Din 8 DB-25 DB-25
1 (HSK0) 20 (DTR) 4 (RTS)
2 (HSK1/Xclk) 6 (DSR) 5 (CTS)
3 (Tx-) 2 (TxData) 2 (TxData)
4 (Gnd) 7 (SigGnd) 7 (SigGnd)
5 (Rx-) 3 (RxData) 3 (RxData)
6 (Tx+) No Connection
7 No Connection
8 (Rx+) No Connection
Since the modem will no longer see DTR from the Mac,
you will have to set the modem to ignore DTR. And
since there is no connection for the DCD, you may as
well set it high on the modem. AT&C0&D0&W0 will do this.
You also have to tell your telecomm software to use
Hardware Handshaking instead of Xon/Xoff.
If your modem supports v.42, you can set the baud rate
in the telecomm program for 4 times the modems top rate.
If you only have MNP5, you can set the telecomm baud
rate for 2 times the modems top rate. This speed between
the computer and modem is called DTE speed and is usually
reported by the CONNECT string. However, this speed
given that you are using hardware handshaking, has little
to do with the speed between the two modems (which is called
DCE speed and is reported by the CARRIER string (if enabled).
When you dial out, the modem will negotiate the highest
speed and level of error correction with the answering
modem. It will probably be lower than your speed between
Mac and modem... that's okay, that's what the handshake is
for.
Hope this helps a bit,
--
Maurice INTERNET: lriggins@blackbird.afit.af.mil (129.92.1.2)
Opinions expressed here do not reflect those of my employer nor
constitute an official position of any U.S.Government agency.russotto@eng.umd.edu (Matthew T. Russotto) (11/28/90)
In article <1990Nov26.183217.236@skbat.csc.ti.com> dittman@skbat.csc.ti.com (Eric Dittman) writes: >[I've figured out that this post didn't make it out earlier, so here is my > request for help again.] > >I'm trying to use hardware handshaking between my Mac IIfx and an ATI 2400etc/e >modem. My cable is wired: > >DIN-8 DB25 >-------------------- >1 20 >2 8 >3 2 >4 7 >5 3 >6 N/C >7 N/C >8 7 > >I've been told this is correct. Nope: DIN8 DB25 -------------------- 1 4 2 5 -- Matthew T. Russotto russotto@eng.umd.edu russotto@wam.umd.edu .sig under construction, like the rest of this campus.