HP 82718A Expansion Pod Reference Manual page 83

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Low-Level Modem Command Dictionary
commands may behave in an unexpected manner. In general, the behavior of multiple dialing commands
is unusual enough that it should be avoided.
Responses: 0, I, 2, 3, S, B
E (ECHO)
I
E eoho specifier
t'10DOUT
II
\E
111
tCHF.::t ( 1 :::)
Enables and disables echoing of low-level modem commands. E 0 enables command echoing--all
low-level commands will be echoed back to the HP-7 S by the modem (actually echoed into the receive
buffer for
t'lOD I t·~:t
to read). E 1 disables command echoing (the carriage return that ends the command
will still be echoed as a carriage return-line feed). The
eoho specifier
is set to 0 when the modem is
initialized, and its current value is preserved while the modem is off.
Responses: none
F (FORMAT)
I
F format speoifier
t'10DOUT
II
~'~F :::
II
tCHF.::t ( 1 :::)
Sets the data format-parity and data length. The
format specifier
is a single digit (0-4) that
specifies the parity and data length. The
format speoifier
is set to 4 when the modem is initialized,
and its current value is preserved while the modem is off. The
format speoifier
has these meanings:
Format
Specifier Parity Data Length
0
Always
1
(mark)
7
bits
1
Always 0 (space)
7
bits
2 Odd 7
bits
3
Even
7
bits
4
None
8
bits
The modem generates parity for all data that is transmitted according to the above table.
If the
high-order bit of a data byte is set, the parity will be generated with the opposite sense. Consequently, if
you need to send legitimate 8-bit data, you should only use F 4, and you will not be able to check parity.
The modem checks for parity errors in all data received for
format speoifiers
0, 1, 2, and 3. If a
parity error is detected, it can be identified with the PAr::: I T\'? high-level modem command. If bit 3 of
JS2
(the second KONTROL parameter) is clear, parity errors will also be flagged by setting the high -order bit
of the bad data byte. In that case the bad data will appear underlined in the HP-7 S display or in inverse
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