HW Assignment Week 4

HW Assignment Week 4

This exercise is due before the 5^th week of class. When you are finished, please email the VI (and any subVI's) to your instructor.

PART I

Make sure that you save this HW VI. You will be able to use it in Lab 4 and subsequent VIs.

In this HW assignment, you will create a typical VI control to communicate to a FICTIONAL instrument.

On the VI front Panel, place a TEXT RING. In the text ring, input the text below corresponding to the appropriate numeric value. (You can right pop-up and use SHOW>DIGITAL DISPLAY to display the numeric value associated with the text.)

Voltage Setting	Numeric Value
10m V	0
100m V	1
1mV	2
10mV	3
100mV	4
500mV	5

Our 'instrument' uses the GPIB command "Set Voltage <n>" to set the voltage to the selected range where <n> is an integer between 0 and 5. In your VI, put the appropriate structures and nodes, etc, to use the control input and write the appropriate string to

A string indicator on the front panel - Can you get the indicator to show the <CR> and <LF> characters in the display?
Our 'instrument' at address 12 using GPIB. For this instrument, the Instrument requires the string to be terminated with a <CR> and <LF>. For example, to set the voltage setting to 10mV, the string

"Set Voltage 3"

should be sent through the GPIB with the proper termination appended.

HINT: Use the FORMAT TO STRING function to create the GPIB string.

HINT: Use the MODE option of the GPIB WRITE function to terminate the string function.

PART II

One of the problems with using Ring controls for GPIB is that Ring controls by their nature are INTEGER outputs. Let's say that our 'Instrument' required the GPIB string to be

"Set Voltage 10mV"

How would you design the VI to generate the appropriate string? Three different methods are listed below. Pick one and describe (you don't need to write the VI) how you would generate the appropriate GPIB string.

Use the numeric output of a RING control and a CASE structure

Use the numeric output of a RING control to pick an element out of an ARRAY CONSTANT.

Use the numeric output of a RING control and the ATTRIBUTE node of the Ring control