Keithley 2657A User Manual

Model 2657A High Power System SourceMeter® Instrument Reference Manual Section 6: Instrument programming
2657A-901-01 Rev. B/December 2012 6-19
You can use parentheses to change the precedences in an expression. The concatenation ("..") and
exponentiation ("^") operators are right associative. All other binary operators are left associative. The
examples below show equivalent expressions.
Equivalent expressions
reading + offset < testValue/2+0.5
=
(reading + offset) <
((testValue/2)+0.5)
3+reading^2*4
=
3+((reading^2)*4)
Rdg < maxRdg and lastRdg <=
expectedRdg
=
(Rdg < maxRdg) and (lastRdg <=
expectedRdg)
-reading^2
=
-(reading^2)
reading^testAdjustment^2
=
reading^(testAdjustment^2)
Conditional branching
Lua uses the if, else, elseif, then, and end keywords to do conditional branching.
Note that in Lua, nil and false are false and everything else is true. Zero (0) is true in Lua.
The syntax of a conditional block is as follows:
if expression then
block
elseif expression then
block
else
block
end
Where:
• expression is Lua code that evaluates to either true or false
• block consists of one or more Lua statements
Example: If
if 0 then
print("Zero is true!")
else
print("Zero is false.")
end
Output:
Zero is true!
Example: Comparison
x = 1
y = 2
if x and y then
print("Both x and y are true")
end
Output:
Both x and y are true

Keithley 2657A Specifications

General

Brand	Keithley
Model	2657A
Category	Measuring Instruments
Language	English