Specifications

Section 7. Measurement Instructions
This Instruction applies an excitation voltage and makes two differential
voltage measurements. The measurements are made on sequential channels.
The result is the voltage measured on the second channel (V
2
) divided by the
voltage measured on the first (V
1
). The result is 1000 times V
2
/ V
1
or
millivolts output per volt of excitation. The connections are made so that V
1
is
the measurement of the voltage drop across the full bridge, and V
2
is the
measurement of the bridge output.
Full Bridge Parameters
Parameter
& Data Type
Enter
Dest
Variable or
Array
The Variable in which to store the results of the instruction. When Reps are used the
results are stored in an array with the variable name. An array must be dimensioned to
have elements for all the Reps.
Reps
Constant
The number of repetitions for the measurement or instruction.
Range
Constant
Alpha Code
Voltage Range
mV5000
± 5000 mV
mV1000
± 1000 mV
mV200
± 200 mV
mV50
± 50 mV
mV20
± 20 mV
Autorange
mV20 − mV5000
Selects range (Sect. 3.1)
mV200C
± 200 mV The mV200C, mV50C, and mV20C
mV50C
± 50 mV ranges pull the channel into common
mV20C
± 20 mV mode range and check for open input
AutorangeC
mV20 − mV200
Selects C range
DiffChan
Constant
The differential channel number on which to make the first measurement. When Reps are
used, subsequent measurements will be automatically made on the following differential
channels. If the channel is entered as a negative number, all reps occur on that channel.
ExChan
Enter the excitation channel number to excite the first measurement.
Constan
Alpha
Code
Code/
Channel
Result
VX1 1 Switched excitation channels, are switched to the excitation
VX2 2 voltage for the measurement and switched off between
VX3 3 measurements
VX4 4
MeasPEx
Constant
The number of sensors to excite with the same excitation channel before automatically
advancing to the next excitation channel. To excite all the sensors with the same excitation
channel, the number should equal the number of Reps.
ExmV
Constant
The excitation voltage in millivolts. Allowable range ± 5000 mV. RevEx may be used to
excite with both a positive and negative polarity to cancel offset voltages.
RevEx
Code Value Result (Reversing requires twice as much time to complete)
Constant False 0 Excite only with the excitation voltage entered
True
≠0
A second measurement is made with the voltage polarity
reversed to cancel offsets
RevDiff Code Value
Result (Reversing requires twice as much time to complete)
Constant False 0
Signal is measured with the high side referenced to the low
True ≠0
A second measurement is made after reversing the inputs to
cancel offsets
7-9