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HP OpenVMS Systemsask the wizard |
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The Question is: trying to setup a modem on ttb0: not familiar with vms so anyhelp would be beneficial. i tried doing the following : set term/perm/alt/modem/speed=9600 ttb0: i connect to the modem and set aa light on , and when the remote person is trying to login , it hangs up on him. thanks The Answer is :
Configuring a modem generally involves setting up the modem control
signals and modem wiring, and setting up the modem to match user and
host system expectations.
As for OpenVMS, your:
$ SET TERMINAL/ALTYPEAHD/MODEM/AUTOBAUD/PERMANENT TTB0:
Will suffice.
You will need to determine if the modem control wires are supported on
the specific serial line port (TTB0:), and you will need to determine
the specific settings of the modem around handling autobaud detection
and the modem control signals.
The modem control signals allow the host and the modem to coordinate
answering the telephone (when the host is up and running and willing
to accept calls) and hanging it up (when the user logs out of the host
or the host crashes).
Access to a testing tool known as a serial line breakout box can greatly
speed the process of wiring up a modem.
The VAXstation 3100 series, for instance, lacks modem control on the
serial line port. And information on the MMJ pinout -- and the MMJ
lacks modem control signal capabilities -- is available in the OpenVMS
Frequently Asked Questions (FAQ) document.
The connections to modems are typically made via the EIA-232 (formerly
known as RS-232) standard pinout. Most any device using EIA-232 will
have the pinout information in its documentation.
The most "interesting" pins in EIA-232 are usually 1, 2, 3, 4, 5, 6,
7, 8, and 20 -- the signal acronyms used below may not be the official
ones from the EIA standard, but they'll give you the idea of what the
pins are used for:
1: fgnd: frame ground
2: txd: transmit data
3: rxd: receive data
4: rts: ready to send
5: cts: clear to send
6: dsr: data set ready
7: sgnd: signal ground
8: cd: carrier detect
20: dtr: data terminal ready
One pinout that the wizard has seen work on most devices and even
with most modems:
1-------1
2-------2
3-------3
4-+ +-4
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5-+ +-5
7-------7
6--+-+--6
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8--+ +--8
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20-+ +--20
The wiring required for a specific device may, of course, vary.
Various configurations require a "crossover" or "modem" cable, which
looks like the above cable, save for a "crossover" in pins 2 & 3:
2-------3
3-------2
Be aware that the modem and the host should be set to negotiate
"limited" modem control. "Full" modem control requires additional
signal wiring, and it does not provide general benefits over the
much simpler "limited" modem control for most users.
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