User Manual

2400 Series SourceMeter
®
User’s Manual SCPI Command Reference 18-27
exist can be listed using the :CATalog? command. The actual math
expression can be read using the :MATH? command. The built-in
math expressions (except POWER) require a two-point sweep in
order to perform the calculation. The “Program fragments” show how
to configure the SourceMeter for these math expressions.
When you want to create a new user-defined math expression, per-
form the following steps in order:
1. If desired, assign units to the calculation result. (See “:UNITs
<name>,” page 18-28.) Units is stored for the calculation.
2. Assign a name to the expression (using up to 10 ASCII charac-
ters) using this command.
3. Define the expression using the: DEFine or EXPRession com-
mand. The new expression is the one that will be presently
selected.
Math expression errors:
+801 “Insufficient vector data” — Returned to idle before acquiring
enough data to fully populate the vector. A CALC1 result is not built.
+804 “Expression list full” — Attempted to create a new expression name
when the list (catalog) is full. The maximum number of user-defined
expression names is five.
+805 “Undefined expression exists” — Attempted to create a new expres-
sion name while a previous expression name remains undefined.
Remember, after creating a name, you have to define the expres-
sion.
+806 “Expression not found” — Attempted to delete a named math
expression that cannot be found.
+807 “Definition not allowed” — Attempted to define an expression that
has not been previously named.
+808 “Expression cannot be deleted” — Attempted to delete one of the
built-in math expressions. (See “:DELete[:SELected] <name>,”
page 18-28.)
+809 “Source memory location revised” — Occurs when a
:SOURce:MEMory sweep location references an expression that
no longer exists.
+811 “Not an operator or number” — Defined a null math expression by
not using a valid operator or number.
+812 “Mismatched parenthesis” — Number of open parentheses must be
the same as the number of closed parentheses. For example,
CALC1:MATH:EXPR (2*sin(VOLT) generates this error.
+813 “Not a number of data handle” — An invalid floating point number or
symbol other than VOLT, CURR, RES, or TIME appears in the
math expression.
+814 “Mismatched brackets” — Improper use of brackets for vectored
math expression indices. For example, CALC1:MATH:EXPR
(VOLT[0*CURR[0]) generates this error.
+815 “Too many parenthesis” — Too many closed parentheses were
detected. For example, CALC1:MATH:EXPR (In(VOLT)) generates
this error.
+816 “Entire expression not parsed” — Occurs when the input expression
does not produce a function for the SourceMeter to calculate.
+817 “Unknown token” — Attempted to define an expression using an
invalid function name.
+818 “Error parsing mantissa” — Occurs when a floating point number
has an invalid mantissa.