Intermec VT220/ANSI, Руководство программиста

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SECTION 8
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Programming
VT220/ANSI Terminal Emulation Programmer’s Reference Guide 8-41
When you combine these hexadecimal values they represent
an 8-bit quantity. This method lets you use any of the 256
character codes in the key string. You can enter key defini-
tion strings in any order.
The default for Stn is “empty.” The key is undefined.
ST is the string terminator. ST (9C hexadecimal) is a C1
8-bit character. You can use ESC \ (1B and 5C hexadeci-
mals) for a 7-bit environment.
Loading UDKs
Following are some guidelines for loading UDKs.
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Clear UDK memory space before loading new defini-
tions. Use a DECUDK string to clear keys without
locking them. Then you can use another DECUDK
string to redefine the keys and lock them.
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If you redefine a key, the old definition is lost. This
may clear some space if the new definition uses fewer
bytes than the old one.
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There are two ways to lock UDKs, but only one way to
unlock them. To lock UDKs, you can use either the
wireless station’s VT220 firmware menus or a
DECUDK control string. To unlock UDKs, you must
use the wireless station’s firmware menus.
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The default value for each key definition is empty.
When you clear UDKs, they are empty.
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An invalid hex pair in a DECUDK string is ignored.
Examples of Device Control Strings
This sequence clears UDKs:
DCS 0 ; 1 | ST
This sequence locks UDKs:
DCS 1 ; 0 | ST