Part 1. Overview
OV-27
OV7. Specifications
Valid for an ambient temperature range of -25°C to +50°C unless otherwise specified
ANALOGUE INPUTS
NUMBER OF CHANNELS: 6 differential or up to 12
single-ended with any combination, software selectable.
Each differential channel can be configured as two
single-ended channels.
CHANNEL EXPANSION: The AM416 Analogue
Multiplexer allows up to 64 single-ended channels to
multiplex into four CR10X single-ended channels. The
AM25T allows 25 thermocouples to multiplex into one
differential channel. Several multiplexers can be
connected to one CR10X.
ACCURACY OF VOLTAGE MEASUREMENTS AND
ANALOGUE OUTPUT VOLTAGES:
±0.
1% of FSR,
±
0.05% of FSR (0 to 40°C).
E.g.
±
0.1% FSR =
±
5.0mV for
±
2500mV range.
RANGE AND RESOLUTION: Ranges are software
selectable for any channel. The resolution for differential
measurements is better than that for single-ended
measurements because two measurements are
averaged together.
Resolution for single-ended measurements is twice the
value shown.
Full Scale Resolution (
µµµµ
V)
Input Range (mV) Differential Single-ended
±2500 333
666
±250 33.3
66.66
±25 3.33
6.66
±7.5 1.00
2.00
±2.5 0.33
0.66
INPUT SAMPLE RATES: The fast or slow A/D
conversion on the four lowest input ranges uses a
250µs or 2.72ms signal integration time, respectively.
Two integrations, separated in time by half of an AC line
cycle, are used with the 60Hz or 50Hz noise rejection
options.
Differential measurements include a second sampling
with reversed input polarity to reduce thermal offset and
common mode errors. Input sample rates are governed
by the time required to measure and convert the result
to engineering units.
TYPICAL INSTRUCTION EXECUTION TIMES:
(depends on input range; times are given for single
measurement. Multiple measurements will be faster -
see table 3-5)
Fast single-ended voltage:
4.7ms
Fast differential voltage:
4.7ms
Slow single-ended voltage:
9.6ms
Slow differential voltage:
9.7ms
Diff. w/50 Hz rejection:
29.9ms
Fast diff. thermocouple:
12.3ms
INPUT NOISE VOLTAGE (for
±
2.5mV range):
Fast differential
-
0.82
µ
V RMS
Slow differential
-
0.25
µ
V RMS
Diff. w/50 Hz rejection
-
0.18
µ
V RMS
COMMON MODE RANGE: ±2.5V
DC COMMON MODE REJECTION: >140dB
NORMAL MODE REJECTION: 70dB at 50Hz with slow
differential measurement (50Hz rejection option).
INPUT CURRENT:
±
9nA max.
INPUT RESISTANCE: 20G
Ω
typical
EXCITATION OUTPUTS
DESCRIPTION: The CR10X has 3 switched
excitations, active only during measurement, with only
one output active at any time. The off state is high
impedance.
RANGE: ±2.5V
RESOLUTION: 0.67mV
ACCURACY:
±
2.5mV (0
°
to +40
°
C)
±
5mV (-25 to +50
°
C)
OUTPUT CURRENT:
±
25mA
FREQUENCY SWEEP FUNCTION: A swept frequency
square wave output between 0 and 2.5V is provided for
vibrating wire transducers. Timing and frequency range
are specified by the instruction.
PERIOD AVERAGING MEASUREMENTS
DEFINITION: The time period for a specified number of
cycles of an input frequency is measured, then divided
by the number of cycles to obtain the average period of
a single cycle. Improved timing resolution and noise
reduction can be obtained by averaging over many
cycles.
INPUTS: Any of the 12 single-ended analogue input
channels can be selected for period averaging. Signal
amplitude reduction or AC coupling is normally required.
INPUT FREQUENCY RANGE:
Range
Peak to Peak Volts
Maximum
Code
Required @ Max. Freq.* Frequency
1
2mv
8kHz
2
5mv
20kHz
3
12mv
40kHz
4
2000mv
200kHz
*AC voltage: must be centred around CR10X ground.
REFERENCE ACCURACY:
±
(0.01% of r
Resolution)
RESOLUTION: The theoretical maximum is 35ns
divided by the number of cycles measured. Resolution
is reduced by signal noise and for signals with a slow
transition through the zero voltage threshold.
TIME REQUIRED FOR MEASUREMENT: Signal
period times the number of cycles measured plus 1.5
cycles.
RESISTANCE & CONDUCTIVITY MEASUREMENTS
ACCURACY: 0.02% of full scale input range used,
limited by the matching bridge resistors. (e.g.
±
0.02% of
±
250mV full-scale input range =
±
100
µ
V.) The excitation
voltage should be programmed so that the bridge output
matches the full scale input voltage range.
MEASUREMENT TYPES: Using the three switched
excitation channels, the CR10X can measure resistance
and conductivity by means of ratiometric bridge
measurements. Standard bridge measurements include
6-wire and 4-wire full bridge, 4-wire, 3-wire and 2-wire
half bridge.
Where appropriate, dual polarity bridge measurements
are used to eliminate DC errors. AC resistance
measurements use a dual polarity 0.75ms excitation
pulse for ionic depolarisation; signal integration occurs
over the last 0.25ms.
PULSE COUNTERS
NUMBER OF PULSE COUNTER CHANNELS:
2 8-bit or 1 16-bit; software selectable.
MAXIMUM COUNT RATE: 16kHz, 8-bit counter;
250kHz, 16-bit counter. Channels are scanned at 8 or
64Hz (software selectable).
MODES: Switch closure, high frequency pulse, and low
level AC.
SWITCH CLOSURE MODE
Minimum Switch Closed Time: 5ms
Minimum Switch Open Time: 6ms
Maximum Bounce Time: 1ms open without being
counted.
HIGH FREQUENCY PULSE MODE
Minimum Pulse Width: 1µs
Maximum Input Frequency: 500kHz
Voltage Thresholds: Count on transition from below
1.5V to above 3.5V
Maximum Input Voltage: ±20V
LOW LEVEL AC MODE
Typical of magnetic pulse flow transducers or other low
voltage, sine wave outputs. (Selected anemometers
etc.)
Input Hysteresis: 8mV.
Maximum AC Input Voltage: 20V RMS
Min. AC Input Voltage:
Range (Hz)
(sine wave mV RMS)*
20
1 to 1000
200
0.5 to 10,000
1000
0.3 to 16,000
*16-bit config. or 64Hz scan requ’d for freq. >2048Hz
DIGITAL I/O PORTS
Eight ports, software selectable as binary inputs or
control outputs. Three ports can be configured to count
pulses or switch closures up to 40Hz.
OUTPUT VOLTAGES (no load): high: 5.0 ± 0.1V;
low < 0.1V.
OUTPUT RESISTANCE: 500 ohms
INPUT STATE: high: 3 to 5.5V: low: -0.5 to 0.8V
INPUT RESISTANCE: 100k
Ω
SDI-12 INTERFACE STANDARD
This communication protocol, developed for
microprocessor-based hydrological and environmental
sensors is included in the CR10X.
SENSOR CONNECTIONS: Digital I/O Port 8 (for
asynchronous communication), 12V power and ground.
Up to ten SDI-12 sensors can be connected to each
port.
10TCRT THERMOCOUPLE REFERENCE
POLYNOMIAL LINEARISATION ERROR: Typically
<
±
0.5C over -35 to +50
°
C range and <
±
0.1
°
C over -24
to +45
°
C range.
INTERCHANGEABILITY ERROR: Typically <
±
0.2
°
C
over 0 to +60
°
C range increasing to
±
0.4
°
C at -35
°
C.
EMI and ESD PROTECTION
Emissions: Meets or exceeds the following standards:
Radiated: per EN 55022:1987 Class B
Conducted: per EN 55022:1987 Class B
Immunity: Meets or exceeds the following standards:
ESD: per IEC 80 1-2: 1984 8kV air discharge
RF: per IEC 80 1-3:1984 3V/m, 27-500 MHz
EFT: per IEC 80 1-4:1988 1kV mains, 500V other
CPU AND INTERFACE
PROCESSOR: Hitachi 6303
MEMORY: 128K Flash and 128K SRAM as standard.
Additional 1Mb Flash is available as an option.
2Mb Flash is available to special order.
STORAGE CAPACITY: The standard CR10X stores
approx. 62,000 data values in Final Storage memory.
The default storage capacity for active programs is 2048
bytes.
CR10X DISPLAY: 8-digit LCD 12.7mm digits
PERIPHERAL INTERFACE: 9-pin D-type connector for
keyboard/display, storage module, modem, printer, card
storage module and RS232 adapter. Baud rates
selectable at 300, 1200, 9600 and 76,800. ASCII
communication protocol is one start bit, one stop bit,
eight data bits (no parity). A baud rate of 76,800 is not
available for communications.
CLOCK ACCURACY: ±1 minute per month
MAXIMUM PROGRAM EXECUTION RATE: System
tasks initiated in sync with real time up to 64Hz. One
measurement with data transfer is possible at this rate
without interruption. A single input can be measured
over short intervals at up to 750Hz using Burst
Measurement mode.
SYSTEM POWER REQUIREMENTS
VOLTAGE: 9.6 to 16 volts
TYPICAL CURRENT DRAIN: Quiescent: 1mA; During
processing: 13mA; During analogue measurement:
46mA average, 50mA peak.
BATTERIES: Any 12V battery can be connected as a
primary power source. Enclosures with power supply
options are available from Campbell Scientific.
Model CR2430 lithium battery is used for clock and
RAM backup, and has a capacity of 270mAh.
DIMENSIONS
SIZE: 198 x 89 x 38mm: 240 x 93 x 75mm with
CR10WP Wiring Panel. Input connectors extend length
by 3.8mm.
WEIGHT: 0.91kg
GUARANTEE
Three years against defects in materials and
workmanship. rev. 26.4.04