String Variables
Because there are so many ways to code numbers, the 1660-series logic
analyzers handle almost all data as ASCII strings. Depending on your host
language, you may be able to use other types when reading in responses.
Sometimes it is helpful to use string variables in place of constants to send
instructions to the 1660-series logic analyzers, such as, including the headers
with a query response.
Example This example combines variables and constants in order to make it easier to
switch from MACHINE1 to MACHINE2. In BASIC, the & operator is used for
string concatenation.
5 OUTPUT XXX;":SELECT 1" !Select the logic analyzer
10 LET Machine$ = ":MACHINE2" !Send all instructions to machine 2
20 OUTPUT XXX; Machine$ & ":TYPE STATE" !Make machine a state analyzer
30 ! Assign all labels to be positive
40 OUTPUT XXX; Machine$ & ":SFORMAT:LABEL ’CHAN 1’, POS"
50 OUTPUT XXX; Machine$ & ":SFORMAT:LABEL ’CHAN 2’, POS"
60 OUTPUT XXX; Machine$ & ":SFORMAT:LABEL ’OUT’, POS"
99 END
If you want to observe the headers for queries, you must bring the returned
data into a string variable. Reading queries into string variables requires little
attention to formatting.
Example This command line places the output of the query in the string variable
Result$.
ENTER XXX;Result$
In the language used for this book (HP BASIC 6.2), string variables are case-
sensitive and must be expressed exactly the same each time they are used.
The output of the logic analyzer may be numeric or character data depending
on what is queried. Refer to the specific commands, in Part 2 of this guide,
for the formats and types of data returned from queries.
Introduction to Programming
String Variables
1–18