Intelligent Instrumentation: Analog Input

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The EDAS-2003M Analog Input Module can read voltage or current inputs. Voltage or current readings can be configured on a channel by channel basis allowing one analog input module to read a combination of voltage or current inputs.

The Analog input module can be used to make a single reading, capture a waveform, or continuously stream data over Ethernet.

The EDAS-2003M-2 has additional hardware to perform waveform capture and streaming at up to 200 kHz.

The EDAS-2003M-3 is also capable of performing waveform capture and streaming at up to 200 kHz. In addition, the -3 module can be used for reading thermocouple inputs. Thermocouple types J, K, T are supported, and when used, require that channel 0 be reserved for CJC compensation. The maximum number of thermocouple inputs possible is 7.

The analog input platform consists of a 16 channel multiplexer (MUX), followed by a programmable gain amplifier (PGA), feeding a 12-bit analog to digital converter (ADC). The output of the ADC is isolated and presented to the system bus. The MUX is capable of providing 16 single-ended inputs, 8 differential inputs or a mixed combination to the PGA. The PGA has gains of 1, 10, and 100. The ADC supports 0-10 V and ±10 V ranges.

The Analog Input Module has sixteen 487-ohm resistors that may be switched between the individual input channels and ground allowing the unit to take current measurements in the 0-20 mA range.

Additionally the module has 100k ohm input ground return resistors that may be switched on to provide an input bias current path for the PGA.

The Analog Input Module includes provisions for pacing (starting) conversions by software or by one of two hardware-based conversion pacing sources. These two hardware sources are an internal 24-bit Rate Generator or a digital input (EXT INT) from an I/O terminal. The EXT INT input may also be used as a trigger signal to control when conversions are started and stopped. This allows for the support of Stop on Trigger, Stop on delay after Trigger, Start on Trigger, and N Conversions after Trigger modes.

The Analog Input Module has a hardware channel scanner that scans channels 0 through N. The scanner increments the channel by one each time a conversion is started and wraps back to channel 0. The value of N is set by software.

The Analog Input Module provides a 24-bit rate generator to pace (start) conversions. The base clock for this rate generator is 4 MHz providing a resolution of 250 nsec. This allows the rate generator to be set to an output range of 2 MHz to 0.238 Hz (4.2 s). The Rate Generator output is also available on the RGOUT terminal on the I/O connector.

Part Number	Analog Input Conversion Throughput
EDAS-2003M-1	2 kHz
EDAS-2003M-2	200 kHz
EDAS-2003M-3 Thermocouple types J, K, T support	200 kHz

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Analog Input Module: EDAS-2003M-1
Parameter	Conditions	Specifications
Inputs		16 Single Ended 8 Differential
Resolution		12-bits (1 in 4096)
Voltage Ranges	Gain=1 Gain=10 Gain=100	± 10V, 0 to 10V ± 1.0V, 0 to 1.0V ± 100mV, 0 to 100mV
Over Voltage Protection	Power On or Off	-40V to +55V
Gain Accuracy	Gain=1 Gain=10 Gain=100	± 0.012% ± 0.05% typical, ±0.25% max ± 0.05% typical, ±0.25% max
Offset Voltage	Gain=1 Gain=10 Gain=100	± 1.2mV ± 0.12mV ± 0.012mV
Input Bias Current		500pA
Input Impedance	Voltage Mode Current Mode	10G ohms \|\| 3pF 487 ohms
Common Mode Range		± 10V
Common Mode Rejection	Gain=1 Gain=10 Gain=100	80dB 86dB 92dB
Noise	Gain=1	0.5 LSB (RMS) 2 LSB (peak to peak)
Linearity		± 1 LSB
Monotonicity	No Missing Codes	12-bits
Rate Generator	Resolution Output Frequency	250 ns 0.238Hz to 200kHz
Isolation	Input to Output VAC RMS for 60 s	1500V
Power Consumption	5VDC	400 mA
Dimensions	Inches mm	4.55D x 5.9H x 1.74W 116D x 150H x 42W
Operating Temperature Range		0 to 60° C^*
^*All specifications are typical at 25° C unless otherwise noted.

EDAS CE Analog Input Modules

Analog I/O: Analog Input Module, with or without thermocouple input, Ordering Information

Specifications

Module Overview