User`s guide

response from the modem before sending the next string. This requires that
word (alphabetic) modem responses are enabled in the modem. If the OK
response does not appear within 4 seconds, HCU will stop waiting and proceed
to the next string.
In most cases the command string arguments need to be terminated with a
carriage return. The carriage return is represented by the “ ! ” character. HCU
will interpret the “! ” character by sending a carriage return (OxOD) to the
modem. HCU will also interpret the “-” character by pausing 500ms. If either
of these characters themselves need to be sent to the modem they can be
escaped with a leading backslash, “\ ! ” or “\ -“. HCU does not send implied
carriage returns at the end of each string.
Spaces may be included in the string arguments.
If you are including space in
an argument you must enclose the string in double quotes or else the DOS
command line interpreter will view the spaces as argument delimiters.
A filename may be used as a source of the string arguments.
The filename
should be preceded by the “@” character, and may be any full pathname. The
structure of the file should be a series of text lines, where each line is a
separate string argument. Command line strings and filename arguments may
be intermixed.
Theory of Operation
Upon execution, HCU will open the network driver, set the driver’s operational
mode to modem support on, force direct mode on (disables any SLTA-10
Adapter network interface protocols, enabling communications with the modem
itself), modem responses on (enables modem responses to be passed to the
host), and reliable transport protocol on. If a serial bit rate has been indicated,
this also is set within the driver.
Next, if the HCU hangup operation is selected, HCU will drop DTR for 500ms.
See Using the SLTA-10 Adapter with a Modem, Chapter 11.
Next, all string arguments are sent to the modem. Acceptable modem
responses to these strings are OK or ERROR.
Next, if the HCU connection operation is selected, HCU will wait for the
connection to be established. This wait will be terminated by one of the
following conditions:
l A response from the modem indicating either success or failure. These responses
may be one of the following.
[CR] is the carriage return (OxOD) character.
CONNECT [anytextl [CR] This indicates a successful connection.
These indicate a failed connection:
NO [anytextl [CR],
BUSY [CR], VOICE [CR1
l Any keyboard action. This will abort the HCU process.
Once the connection is considered made, HCU will process any additional
modem responses for a few seconds. It will then change the operational mode
of the network driver to force direct mode off and modem responses off.
If this
SLTA-10 Adapter User’s Guide
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