Cr9060 excitation module – Campbell Scientific CR9000X Measurement and Control System User Manual
Page 47
Overview
CR9060 Excitation Module
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9060 EXCITATION
C.A.O.
SWITCHED EXCITATION
DIGITAL CONTROL OUTPUT
MADE
IN USA
FIGURE OV1-11. CR9060
The CR9060 is the Excitation Module for the CR9000X Measurement and
Control System. The CR9060 module has 6 Continuous Analog Outputs
(CAO), 10 Switched Excitation, and 8 Control Ports.
CAOs: The CR9060 Excitation Module has six continuous analog outputs with
individual digital-to-analog converters for PID Algorithm, waveform
generation, and excitation for bridge measurements. The six CAOs can be
controlled independently, or can be turned on simultaneously.
Switched Excitation: The CR9060 also has ten switched excitation channels
that provide precision voltages for bridge measurements. Only 1 switched
excitation is active at a time, where all 6 of the CAOs can be turned on
simultaneously. The advantage of using switched excitation is that it requires
less power and it reduces, or eliminates, self-heating sensor errors, as the on
time of the excitation is limited.
The ten switched and six continuous analogue output excitation channels can
be set to any value within the range of ±5 VDC with a compliance current of
50 mA. Again, only one switched excitation can be on at a time.
Control Ports: The CR9060 also has 8 built in control ports (output only).
These can be set to TTL levels (0 Volts or 5 Volts). These ports can be used to
activate external relays, or simply to toggle the state of LEDs for monitoring
purposes. The output resistance of these ports is 100 ohms, so the current drive
is rather limited.
CR9060 Supported measurement Instructions
BrFull
Requires CR9050(1)
Full Bridge
BrFull6W Requires CR9050(1)
6 Wire Full Bridge
BrHalf
Requires CR9050(1)
Half Bridge
BrHalf3W Requires CR9050(1)
3 Wire Half Bridge
BrHalf4W Requires CR9050(1)
4 Wire Half Bridge
CR9060 Supported control Instructions
Excite
Sets a CAO or Switched Excite Channel
PortSet
Sets the logic level of a Single Control Port
WriteIO
Sets the logic level of a group of Control Ports
See Section 3.1.5 Bridge Resistance Measurements for measurement details.
See Section 7 Measurement Instructions for Measurement Instruction details.
See Section 9.2 Data Logger Status/Control for Control Instruction details.
OV-15