Vishay Micro-Measurements
System 7000 Programmer’s Reference Manual
Page 131 of 142
7.4.6.11 Set LVDT Demodulator Source
Length
Command
Group
Command
Code
Card Mask
Channel
Mask
Parameters
0x0007
0x06
0x0014
Used
Ignored
0x00
Byte 8:
Demodulator Source
Value
Demodulator Source
0x00
Positive Reference
1
(default)
0x01
Negative Reference
2
0x02
Common Mode Reference (Secondary)
0x03
Excitation Reference (Primary)
12
Selects the triggering source for the demodulator. The Primary selection is used for 4-wire LVDTs or for
LVDTs that don’t have sufficient common-mode output signal to trigger the secondary winding. The
secondary selection is preferred for 6-, 5-, and 3-wire LVDTs. In this mode, the demodulator trigger is
sourced directly from the secondary winding of the LVDT.
The Positive Reference is the default state and should be selected when excitation is disabled to prevent
oscillation. The System 7000 automatically sets the demodulator source to Positive Reference when the
excitation is disabled. See the ConfigureLVDTCardExcitation method.