Campbell Scientific CR23X Micrologger - Manual (Page 33)

CR23X MICROLOGGER OVERVIEW
OV-23
OV7. SPECIFICATIONS
PROGRAM EXECUTION RATE
Program is synchronized with real-time up to 100 Hz.
Two fast (250 µs integration) single-ended measure-
ments can write to final storage at 100 Hz. Burst
measurements are possible at rates up to 1.5 kHz over
short intervals.
CLOCK ACCURACY
±1 minute per month
ANALOG INPUTS
DESCRIPTION: 12 differential or 24 single-ended,
individually configured. Channel expansion
provided through AM416 Relay Multiplexers and
AM25T Thermocouple Multiplexers.
ACCURACY: ±0.025% of FSR; 0° to 40°C
±0.05% of FSR; -25° to 50°C
±0.075% of FSR; -40° to 80°C (optional)
±5 µV offset voltage error is possible with SE
measurements.
RANGES AND RESOLUTION
Input Resolution (µV) Accuracy (mV)
Range (mV) Diff. SE (-25° to 50°C)
±5000 166 333 ±5.00
±1000 33.3 66.6 ±1.00
±200 6.66 13.3 ±0.20
±50 1.67 3.33 ±0.05
±10 0.33 0.66 ±0.01
INPUT SAMPLE RATES: Includes the measurement
time and conversion to engineering units. Differ-
ential measurements incorporate two integra-
tions with reversed input polarities to reduce
thermal offset and common mode errors. Fast
measurement integrates the signal for 250 µs;
slow measurement integrates for one power
line cycle (50 or 60 Hz).
Fast single-ended voltage: 2.1 ms
Fast differential voltage: 3.1 ms
Slow single-ended voltage (60 Hz): 18.3 ms
Slow differential voltage (60 Hz): 35.9 ms
Fast differential thermocouple: 6.9 ms
INPUT REFERRED NOISE: Typical for ±10 mV Input
Range; digital resolution dominates for higher
ranges.
Fast differential 0.60 µV rms
Slow differential (60 Hz) 0.15 µV rms
Fast single-ended 1.20 µV rms
Slow single-ended (60 Hz) 0.30 µV rms
COMMON MODE RANGE: ±5 V.
DC COMMON MODE REJECTION: >100 dB.
NORMAL MODE REJECTION: 70 dB (60 Hz with slow
diff. measurement).
SUSTAINED INPUT VOLTAGE WITHOUT DAMAGE:
±16 VDC max.
INPUT CURRENT: ±2.5 nA typ., ±10 nA max. at 50°C.
INPUT RESISTANCE: 20 Gohms typical.
ANALOG OUTPUTS
DESCRIPTION: 4 switched, active only during
measurement one at a time; 2 continuous.
RANGE: Programmable between ±5 V
RESOLUTION: 333 µV
ACCURACY: ±5 mV; ±2.5 mV (0° to 40°C).
CURRENT SOURCING: 50 mA for switched; 15 mA
for continuous.
CURRENT SINKING: 50 mA for switched, 5 mA for
continuous (15 mA for continuous with Boost
selected in P133).
FREQUENCY SWEEP FUNCTION: The switched
outputs provide a programmable swept frequency,
0 to 5 V square wave for exciting vibrating wire
transducers.
RESISTANCE MEASUREMENTS
MEASUREMENT TYPES: The CR23X provides ratio-
metric measurements of 4- and 6-wire full bridges,
and 2-, 3-, and 4-wire half bridges. Precise, dual
polarity excitation using any of the 4 switched
outputs eliminates DC errors. Conductivity
measurements use a dual polarity 0.75 ms excita-
tion to minimize ionic polarization errors.
ACCURACY: ±0.02% of FSR (±0.015%, 0° to 40°C)
plus bridge resistor error.
PERIOD AVERAGING MEASUREMENTS
DESCRIPTION: The average period for a single
cycle is determined by measuring the duration
of a specified number of cycles. Any of the 24
SE analog inputs can be used; signal attenuation
and AC coupling is typically required.
INPUT FREQUENCY RANGE: Signal centered
around ground.
Max. Input Min. signal (Peak to Peak)
Frequency @ Max. Freq.
10 kHz 2 mV
20 kHz 5 mV
30 kHz 10 mV
200 kHz 500 mV
RESOLUTION: 12 ns divided by the number of cycles
measured.
ACCURACY: ±0.03% of reading.
PULSE COUNTERS
DESCRIPTION: Four 8-bit or two 16-bit inputs
selectable for switch closure, high frequency pulse,
or low-level AC. Counters read at 10 or 100 Hz.
MAXIMUM COUNT RATE: 2.5 kHz and 25 kHz, 8-bit
counter read at 10 Hz and 100 Hz, respec-
tively; 500 kHz, 16-bit counter.
SWITCH CLOSURE MODE
Minimum Switch Closed Time: 5 ms.
Minimum Switch Open Time: 6 ms.
Maximum Bounce Time: 1 ms open without being
counted.
HIGH FREQUENCY PULSE MODE
Minimum Pulse Width: 1 µs.
Maximum Input Frequency: 500 kHz.
Voltage Thresholds: Count upon transition from
below 1.5 V to above 3.5 VDC. Larger transitions
required at high frequencies because of 0.5 µs
time constant filter.
Maximum Input Voltage: ±20 V.
LOW LEVEL AC MODE
Internal AC coupling removes DC offsets up to
±0.5 V.
Input Hysteresis: 15 mV.
Maximum AC Input Voltage: ±20 V.
Frequency Range Min. sine wave rms
1.0 Hz to 1 kHz 20 mV
0.5 Hz to 10 kHz 200 mV
0.3 Hz to 16 kHz 1000 mV
DIGITAL I/O PORTS
DESCRIPTION: 8 ports selectable as binary inputs or
control outputs. Ports C5-C8 capable of counting
switch closures and high frequency.
HIGH FREQUENCY MAX: 2.5 kHz
OUTPUT VOLTAGES (no load): high 5.0 V ±0.1 V;
low < 0.1 V.
OUTPUT RESISTANCE: 500 ohms.
INPUT STATE: high 3.0 to 5.5 V; low -0.5 to 0.8 V.
INPUT RESISTANCE: 100 kohms.
SDI-12 INTERFACE SUPPORT
DESCRIPTION: Digital I/O Ports C5-C8 support SDI-
12 asynchronous communication; up to 10 SDI-12
sensors can be connected to each port.
EMI and ESD PROTECTION
Encased in metal with gas discharge tubes on the
panel, the CR23X has EMI filtering and ESD protection
on all input and output connections.
CE COMPLIANCE (as of 01/98)
APPLICATION OF COUNCIL DIRECTIVE(S):
89/336/EEC as amended by 89/336/EEC and
93/68/EEC
STANDARD(S) TO WHICH CONFORMITY IS
DECLARED:
ENC55022-1: 1995 and ENC50082-1: 1992
CPU AND INTERFACE
PROCESSORS: Hitachi 6303; Motorola 68HC708
supports communications.
MEMORY: 1 M Flash stores 500K data values;
512K Flash stores OS and user programs with
128K battery-backed SRAM. Optional 4 M Flash
available.
DISPLAY: 24-character-by-2-line LCD.
SERIAL INTERFACES: Optically isolated RS-232
9-pin interface for computer or modem. CS 9-pin
I/O interface for peripherals such as card storage
module or modem.
BAUD RATES: Selectable at 300, 1200, 2400, 4800,
9600, 19.2K, 38.4K, and 76.8K. ASCII protocol
is one start bit, one stop bit, eight data bits, no
parity.
SYSTEM POWER REQUIREMENTS
VOLTAGE: 11 to 16 VDC.
TYPICAL CURRENT DRAIN: 2 mA quiescent with
display off (2.5 mA max), 7 mA quiescent with
display on, 45 mA during processing, and
70 mA during analog measurement.
INTERNAL BATTERIES: 7 Ahr alkaline or 7 Ahr
rechargeable base; low-profile base without bat-
teries optional. 1800 mAhr lithium battery for clock
and SRAM backup typically provides 10 years of
service.
EXTERNAL BATTERIES: Any 11 to 16 V battery
may be connected; reverse polarity protected.
PHYSICAL SPECIFICATIONS
SIZE: 9.5” x 7.0” x 3.8” (24.1 cm x 17.8 cm x 9.6 cm).
Terminal strips extend 0.4” (1.0 cm) and terminal
strip cover extends 1.3” (3.3 cm) above the panel
surface.
WEIGHT: 3.6 lbs (1.6 kg) with low-profile base,
8.3 lbs (3.8 kg) with alkaline base,
10.7 lbs (4.8 kg) with rechargeable base.
WARRANTY
3 years against defects in materials and workmanship.
Electrical specifications are valid for -25° to 50°C range unless otherwise specified. To maintain electrical specifications, yearly recalibrations are recommended.