VXI VT1422A - Manual (Page 59)

Programming the VT1422A & VT1529A/B for Remote Strain Measurement 57 Chapter 3
Chapter 3
Programming the VT1422A & VT1529A/B
for Remote Strain Measurement
About This Chapter
This chapter describes using the VT1422A in combination with the
VT1539A Remote Channel SCP and VT1529A/B Remote Strain
Conditioning Units to make large channel count strain measurements. The
system is shown being used strictly in a data acquisition mode where, after
configuration, it is driven by a user-defined channel list (the Scan List) and
sends the measurements to the unit’s FIFO buffer and Current Value Table
(CVT) for transfer to the computer. Of course, control algorithms can also
be created that execute concurrently with the Scan List driven data
acquisition operation. Chapter 4 and Chapter 6 cover general data
acquisition and control programming with algorithms. This chapter assumes
that the user is an expert when it comes to making strain measurements, so
this chapter simply illustrates how to make strain measurements with the
VXI Technology Remote Strain Measuring System (VT1422A, VT1539A,
and VT1529A/B). The chapter will cover:
• Instrument Setup for Remote Strain Measurements . . . . . . . . page 58
-- Preparing the VT1422A for Installation . . . . . . . . . . . . . . . page 58
-- Preparing the VT1529A/B for Use . . . . . . . . . . . . . . . . . . . page 59
-- Installing User Selected 1/4 Bridge Resistors (Optional) . . page 59
-- Connecting VT1529A/Bs to the VT1422A. . . . . . . . . . . . . page 62
-- Connecting Excitation Supplies . . . . . . . . . . . . . . . . . . . . . page 67
• Connecting the VT1529A/B to Strain Gages . . . . . . . . . . . . . page 69
-- Channel Connector Pin-to-Signal Relationship . . . . . . . . . page 69
• VT1529A/B Bridge Configurations . . . . . . . . . . . . . . . . . . . . page 70
• Connecting to the VT1529A/Bs Dynamic Strain Ports . . . . . page 73
-- Dynamic Strain Port Offset Control . . . . . . . . . . . . . . . . . . page 75
• Remote Strain Channel Addressing . . . . . . . . . . . . . . . . . . . . page 76
-- Runtime Remote Scan Verification . . . . . . . . . . . . . . . . . . . page 76
• Programming for Remote Strain Measurement . . . . . . . . . . . page 78
-- Description of Strain Measurement . . . . . . . . . . . . . . . . . . page 78
Measure Strain Using Built-in Strain EU Conversion . . page 79
Measure Strain Using User Specified EU Conversion . . page 83
Measure Bridge Voltages and Convert to Strain . . . . . . . page 86
• Verifying Correct Bridge Completion (Shunt Cal) . . . . . . . . . page 90
• Built-in Strain Conversion Equations . . . . . . . . . . . . . . . . . . . page 92