Analog Input Products

Analog Input Products


Analog input boards are useful for measuring variably changing conditions in the real world. When we want to measure these variably changing conditions, we need analog inputs to convert these changing real world conditions to changing electrical quantities. For example, monitoring the temperature inside a wood kiln, or the water pressure on the output of a pump, or the heart rate of a medical patient. In each of these cases, you can use one of our analog input devices to convert the electrical data from a sensor or transducer into binary data that can then be used by your computer. The device that converts this data is known as an analog to digital converter (abbreviated ADC, A/D, or A to D). An analog input is a measurable electrical signal with a defined range. The analog input changes continuously in a definable manner in relation to the measured property. This data is very useful for process monitoring, process control, or simple monitoring / data collection and acquisition. ACCES’ analog input boards amplify and multiplex input signals from thermocouples, strain gauges, accelerometers, photo sensors, flowmeters, RTDs, thermistors, voltage sources, millivolt sources, and current sources, just to name a few.

There are basically three types of analog input signals used to measure these conditions. They are voltage, current, and resistance.

If voltage mode is used, analog input connections can be either single-ended or differential. Low per-channel cost is a major advantage of using single-ended inputs because only one multiplexer switch is needed per channel and there is less system wiring. Single-ended inputs all share a common return or ground line. The measurement is the difference between the signal and the ground. Only the “high” signal wires are connected through the amplifier and multiplexer. The “low” wires return through the system ground connections. That is, both the signal source and the amplifier are referenced to ground. This arrangement works fine as long as the ground potential difference is very small. However, if there is a large difference in ground potential, extraneous currents can flow and generate errors. This is called a “ground loop”. Ground potential differences (ground loops) can cause larger interference problems than electromagnetic fields. Ground loops occur if the sensors are tied to a local ground. That local ground can be many volts different from the ground potential at the receiving circuit. Single-ended measurements are also more susceptible to noise than differential measurements due to differences in the signal paths and the tendency to pick up surrounding electrical activity. With single-ended inputs you have no way of distinguishing between the signal and the noise.

To avoid this problem, a differential-input connection can be used with an amplifier that has a high common mode rejection ratio. A differential arrangement connects both ends of the signal source to the inverting and non-inverting inputs of the amplifier. Measurement is the difference in voltage between the input and the reference, which helps to reduce noise and any voltage that is common to both wires. Twisting wires together will ensure that any noise picked up will be the same for each wire. In this way, voltage due to ground loops appears as a common mode voltage and can be rejected by the common-mode-rejection properties of the amplifier. An instrumentation type amplifier (rather than a simple operational amplifier) is required and two multiplexer switches are required per channel. An obvious disadvantage of differential inputs is that you need twice as many wires, so you can connect only half the number of signals, compared to single-ended inputs.

If you have signals larger than 1V, short signal wires, and close together signal sources, single-ended inputs should be fine. If your application falls outside these boundaries, differential inputs would be the wise choice.

In industrial applications, where wiring can be very long, it is common to use “current transmitters”; i.e., devices located at or near the transducer which convert the sensor output to an analog current signal (e.g. 4 to 20 mA). Current signals are sometimes used because they are relatively immune to errors such as induced noise and voltage drops due to lead resistance. and have become a de facto standard for critical process control measurements. Another plus is that it saves money due to reduced wiring cost. Current mode operation is somewhat susceptible to magnetically-induced errors. The simplest solution is to use twisted-pair signal lines and to keep those lines remote from power lines or other sources of magnetic induction. Also, at the receiving circuit, the signal usually must be converted into a voltage and level-shifted to a zero-based range so that it can be digitized using the full input capability of the digitizer.

Resistance measurement is most commonly associated with direct inputs from temperature sensing devices, such as thermistors and resistance temperature detectors (RTDs). RTDs are temperature sensors that exploit the predictable change in electrical resistance of some materials with changing temperature. They are slowly replacing the use of thermocouples in many industrial applications below 600°C, due to higher accuracy and repeatability. Thermistors are widely used as inrush current limiters, temperature sensors, self-resetting overcurrent protectors, and self-regulating heating elements. Thermistors differ from RTDs in that the material used in a thermistor is generally a ceramic or polymer, while RTDs use pure metals. The temperature response is also different; RTDs are useful over larger temperature ranges, while thermistors typically achieve a higher precision within a limited temperature range (usually -90°C to 130°C).

A wide range of flexible signal conditioning types per channel are also offered. These include options such as RC filters on each input, voltage dividers on each input, 4-20mA current inputs, thermocouples (temp sensor for cold junction), RTD measurement, as well as bridge completion.

For applications requiring analog inputs only, a line of cost efficient USB products offers all of the features described above except no analog outputs are included.

Signal conditioning is an essential requirement in many applications and systems which demand accurate and precise measurements. Signal conditioning circuits convert one type of electronic signal into another type of signal that can be used to improve and enhance the data acquisition system and application. Sometimes the data acquisition card that you plug into the computer provides necessary conditioning; sometimes that signal conditioning must be done external to the computer. In general, signal conditioning consists of amplification, isolation, filtering, sensor excitation, cold-junction compensation and more.

Signal inputs accepted by our signal conditioners include DC voltage/current and AC voltage/current. Sensor inputs can be accelerometer, thermocouple, thermistor, resistance thermometer (RTDs), strain gauge or bridge, and LVDT/RVDTs. Signal conditioned outputs include voltage, current, frequency, relay, isolation, and more.

ACCES offers a wide variety of external signal conditioning products which include analog, digital, and serial signal conditioning. Sometimes the data acquisition product you plug into the computer provides the necessary conditioning; and sometimes that signal conditioning must be done external to the computer.

Click the following wikipedia links to learn more about analog inputs, signal conditioning and data acquisition in general.

Multifunction Analog Input/Output DAQ on PCI Express Mini Card (mPCIe)

Model# of InputsResBip RngSpeed# DACsDigital I/OXThf:att:pa_inputshf:att:pa_res-inputhf:att:pa_bip-rg-inputhf:att:pa_speedhf:att:pa_outputshf:att:pa_digital-i-ohf:att:pa_xt
mPCIe-AIO16-16F16 SE, 8 DIF1671MHz ×242 I/OYesShow details16-se-8-dif1671mhz-x242-i-oyes
mPCIe-AIO16-16A16 SE, 8 DIF167500kHz42 I/OYesShow details16-se-8-dif167500khz42-i-oyes
mPCIe-AIO16-16E16 SE, 8 DIF167250kHz42 I/OYesShow details16-se-8-dif167250khz42-i-oyes
mPCIe-AI16-16F16 SE, 8 DIF1671MHz ×22 I/OYesShow details16-se-8-dif1671mhz-x26342-i-oyes
mPCIe-AI16-16A16 SE, 8 DIF167500kHz2 I/OYesShow details16-se-8-dif167500khz6342-i-oyes
mPCIe-AI16-16E16 SE, 8 DIF167250kHz2 I/OYesShow details16-se-8-dif167250khz6342-i-oyes
mPCIe-AIO12-16A16 SE, 8 DIF127500kHz42 I/OYesShow details16-se-8-dif127500khz42-i-oyes
mPCIe-AIO12-1616 SE, 8 DIF127250kHz42 I/OYesShow details16-se-8-dif127250khz42-i-oyes
mPCIe-AIO12-16E16 SE, 8 DIF127100kHz42 I/OYesShow details16-se-8-dif127100khz42-i-oyes
mPCIe-AI12-16A16 SE, 8 DIF127500kHz2 I/OYesShow details16-se-8-dif127500khz6342-i-oyes
mPCIe-AI12-1616 SE, 8 DIF127250kHz2 I/OYesShow details16-se-8-dif127250khz6342-i-oyes
mPCIe-AI12-16E16 SE, 8 DIF127100kHz2 I/OYesShow details16-se-8-dif127100khz6342-i-oyes
mPCIe-ADIO16-8F8 SE, 4 Diff1671MHz416 I/OYesShow details8-se-4-diff1671mhz416-i-oyes
mPCIe-ADIO16-8A8 SE, 4 Diff167500kHz416 I/OYesShow details8-se-4-diff167500khz416-i-oyes
mPCIe-ADIO16-8E8 SE, 4 Diff167250kHz416 I/OYesShow details8-se-4-diff167250khz416-i-oyes
mPCIe-ADI16-8F8 SE, 4 Diff1671MHz16 I/OYesShow details8-se-4-diff1671mhz63416-i-oyes
mPCIe-ADI16-8A8 SE, 4 Diff167500kHz16 I/OYesShow details8-se-4-diff167500khz63416-i-oyes
mPCIe-ADI16-8E8 SE, 4 Diff167250kHz16 I/OYesShow details8-se-4-diff167250khz63416-i-oyes
mPCIe-ADIO12-8A8 SE, 4 Diff127500kHz416 I/OYesShow details8-se-4-diff127500khz416-i-oyes
mPCIe-ADIO12-88 SE, 4 Diff127250kHz416 I/OYesShow details8-se-4-diff127250khz416-i-oyes
mPCIe-ADIO12-8E8 SE, 4 Diff127100kHz416 I/OYesShow details8-se-4-diff127100khz416-i-oyes
mPCIe-ADI12-8A8 SE, 4 Diff127500kHz16 I/OYesShow details8-se-4-diff127500khz63416-i-oyes
mPCIe-ADI12-88 SE, 4 Diff127250kHz16 I/OYesShow details8-se-4-diff127250khz63416-i-oyes
mPCIe-ADI12-8E8 SE, 4 Diff127100kHz16 I/OYesShow details8-se-4-diff127100khz63416-i-oyes

Multifunction Analog Input/Output DAQ on USB

Model# of InputsResSpeed Bip RngUni RngAutocalFIFO# DACshf:att:pa_inputshf:att:pa_res-inputhf:att:pa_speedhf:att:pa_bip-rg-inputhf:att:pa_uni-rg-inputhf:att:pa_autocalhf:att:pa_fifohf:att:pa_outputs
USBP-II8IDO4A2 SE164kHz1NoNoShow details2-se164khz6411nono634
USB-AIO16-16F16 SE, 8 DIF161MHz44YesYes2 or 4Show details16-se-8-dif161mhz44yesyes2-or-4
USB-AIO16-16A16 SE, 8 DIF16500kHz44YesYes2 or 4Show details16-se-8-dif16500khz44yesyes2-or-4
USB-AIO16-16E16 SE, 8 DIF16250kHz44RefsYes2 or 4Show details16-se-8-dif16250khz44refsyes2-or-4
USB-AI16-16F16 SE, 8 DIF161MHz44YesYesShow details16-se-8-dif161mhz44yesyes634
USB-AI16-16A16 SE, 8 DIF16500kHz44YesYesShow details16-se-8-dif16500khz44yesyes634
USB-AI16-16E16 SE, 8 DIF16250kHz44RefsYesShow details16-se-8-dif16250khz44refsyes634
USB-AIO12-16A16 SE, 8 DIF12500kHz44YesYes2 or 4Show details16-se-8-dif12500khz44yesyes2-or-4
USB-AIO12-1616 SE, 8 DIF12250kHz44RefsYes2 or 4Show details16-se-8-dif12250khz44refsyes2-or-4
USB-AIO12-16E16 SE, 8 DIF12100kHz44NoYes2 or 4Show details16-se-8-dif12100khz44noyes2-or-4
USB-AI12-16A16 SE, 8 DIF12500kHz44YesYesShow details16-se-8-dif12500khz44yesyes634
USB-AI12-1616 SE, 8 DIF12250kHz44RefsYesShow details16-se-8-dif12250khz44refsyes634
USB-AI12-16E16 SE, 8 DIF12100kHz44NoYesShow details16-se-8-dif12100khz44noyes634
USB-AI16-2A2161MHz ×244NoYesShow details2161mhz-x244noyes634
USB-AI12-1616 SE, 8 DIFShow details16-se-8-dif

DAQ-PACK Multifunction 64-Channel Count Economy Analog Input/Output Products on USB

Model# of InputsResSpeed Bip RngUni RngAutocalFIFO# DACshf:att:pa_inputshf:att:pa_res-inputhf:att:pa_speedhf:att:pa_bip-rg-inputhf:att:pa_uni-rg-inputhf:att:pa_autocalhf:att:pa_fifohf:att:pa_outputs
DPK-AI12-64ME64 SE, 32 DIF12100kHz42NoYesShow details64-se-32-dif12100khz42noyes634
DPK-AI12-64M64 SE, 32 DIF12250kHz42RefsYesShow details64-se-32-dif12250khz42refsyes634
DPK-AI12-64MA64 SE, 32 DIF12500kHz42YesYesShow details64-se-32-dif12500khz42yesyes634
DPK-AIO12-64ME64 SE, 32 DIF12100kHz42NoYes2Show details64-se-32-dif12100khz42noyes2
DPK-AIO12-64M64 SE, 32 DIF12250kHz42RefsYes2Show details64-se-32-dif12250khz42refsyes2
DPK-AIO12-64MA64 SE, 32 DIF12500kHz42YesYes2Show details64-se-32-dif12500khz42yesyes2
DPK-AI16-64ME64 SE, 32 DIF16250kHz42RefsYesShow details64-se-32-dif16250khz42refsyes634
DPK-AI16-64MA64 SE, 32 DIF16500kHz42YesYesShow details64-se-32-dif16500khz42yesyes634
DPK-AIO16-64ME64 SE, 32 DIF16250kHz42RefsYes2Show details64-se-32-dif16250khz42refsyes2
DPK-AIO16-64MA64 SE, 32 DIF16500kHz42YesYes2Show details64-se-32-dif16500khz42yesyes2

DAQ-PACK High Channel Count Flexible Signal Conditioning Multifunction Analog Input/Output Products on USB

Model# of InputsResSpeed Bip RngUni RngAutocalFIFO# DACshf:att:pa_inputshf:att:pa_res-inputhf:att:pa_speedhf:att:pa_bip-rg-inputhf:att:pa_uni-rg-inputhf:att:pa_autocalhf:att:pa_fifohf:att:pa_outputs
DPK-AIO12-128E128 DIF12100kHz99NoYes2Show details128-dif12100khz99noyes2
DPK-AIO12-128128 DIF12250kHz99RefsYes2Show details128-dif12250khz99refsyes2
DPK-AIO12-128A128 DIF12500kHz99YesYes2Show details128-dif12500khz99yesyes2
DPK-AI12-128E128 DIF12100kHz99NoYesShow details128-dif12100khz99noyes634
DPK-AI12-128128 DIF12250kHz99RefsYesShow details128-dif12250khz99refsyes634
DPK-AI12-128A128 DIF12500kHz99YesYesShow details128-dif12500khz99yesyes634
DPK-AIO16-128E128 DIF16250kHz99RefsYes2Show details128-dif16250khz99refsyes2
DPK-AIO16-128A128 DIF16500kHz99YesYes2Show details128-dif16500khz99yesyes2
DPK-AI16-128E128 DIF16250kHz99RefsYesShow details128-dif16250khz99refsyes634
DPK-AI16-128A128 DIF16500kHz99YesYesShow details128-dif16500khz99yesyes634
DPK-AIO12-32E32 DIF12100kHz99NoYes2Show details32-dif12100khz99noyes2
DPK-AIO12-3232 DIF12250kHz99RefsYes2Show details32-dif12250khz99refsyes2
DPK-AIO12-32A32 DIF12500kHz99YesYes2Show details32-dif12500khz99yesyes2
DPK-AI12-32E32 DIF12100kHz99NoYesShow details32-dif12100khz99noyes634
DPK-AI12-32A32 DIF12500kHz99YesYesShow details32-dif12500khz99yesyes634
DPK-AI12-3232 DIF12250kHz99RefsYesShow details32-dif12250khz99refsyes634
DPK-AIO16-32E32 DIF16250kHz99RefsYes2Show details32-dif16250khz99refsyes2
DPK-AIO16-32A32 DIF16500kHz99YesYes2Show details32-dif16500khz99yesyes2
DPK-AI16-32A32 DIF16500kHz99YesYesShow details32-dif16500khz99yesyes634
DPK-AI16-32E32 DIF16250kHz99RefsYesShow details32-dif16250khz99refsyes634
DPK-AIO12-64E64 DIF12100kHz99NoYes2Show details64-dif12100khz99noyes2
DPK-AIO12-6464 DIF12250kHz99RefsYes2Show details64-dif12250khz99refsyes2
DPK-AIO12-64A64 DIF12500kHz99YesYes2Show details64-dif12500khz99yesyes2
DPK-AI12-64E64 DIF12100kHz99NoYesShow details64-dif12100khz99noyes634
DPK-AI12-6464 DIF12250kHz99RefsYesShow details64-dif12250khz99refsyes634
DPK-AI12-64A64 DIF12500kHz99YesYesShow details64-dif12500khz99yesyes634
DPK-AIO16-64E64 DIF16250kHz99RefsYes2Show details64-dif16250khz99refsyes2
DPK-AIO16-64A64 DIF16500kHz99YesYes2Show details64-dif16500khz99yesyes2
DPK-AIO12-96E96 DIF12100kHz99NoYes2Show details96-dif12100khz99noyes2
DPK-AIO12-9696 DIF12250kHz99RefsYes2Show details96-dif12250khz99refsyes2
DPK-AIO12-96A96 DIF12500kHz99YesYes2Show details96-dif12500khz99yesyes2
DPK-AI12-96E96 DIF12100kHz99NoYesShow details96-dif12100khz99noyes634
DPK-AI16-64E64 DIF16250kHz99RefsYesShow details64-dif16250khz99refsyes634
DPK-AI12-9696 DIF12250kHz99RefsYesShow details96-dif12250khz99refsyes634
DPK-AI16-64A64 DIF16500kHz99YesYesShow details64-dif16500khz99yesyes634
DPK-AI12-96A96 DIF12500kHz99YesYesShow details96-dif12500khz99yesyes634
DPK-AIO16-96A96 DIF16500kHz99YesYes2Show details96-dif16500khz99yesyes2
DPK-AIO16-96E96 DIF16250kHz99RefsYes2Show details96-dif16250khz99refsyes2
DPK-AI16-96E96 DIF16250kHz99RefsYesShow details96-dif16250khz99refsyes634
DPK-AI16-96A96 DIF16500kHz99YesYesShow details96-dif16500khz99yesyes634

Multifunction Analog Input/Output DAQ on PCI

Model# of InputsResSpeed Bip RngUni RngAutocalFIFO# DACshf:att:pa_inputshf:att:pa_res-inputhf:att:pa_speedhf:att:pa_bip-rg-inputhf:att:pa_uni-rg-inputhf:att:pa_autocalhf:att:pa_fifohf:att:pa_outputs
PCI-AI12-1616 SE, 8 DIF12100kHz44NoShow details16-se-8-dif12100khz44no
PCI-AI12-16A16 SE, 8 DIF12100kHz44YesShow details16-se-8-dif12100khz44yes
PCI-A12-16A16 SE, 8 DIF12100kHz44YesShow details16-se-8-dif12100khz44yes
LPCI-AIO16E16 SE, 8 DIF16250kHz64RefsYes2Show details16-se-8-dif16250khz64refsyes2
LPCI-AIO16A16 SE, 8 DIF16500kHz64RefsYes2Show details16-se-8-dif16500khz64refsyes2

Multifunction Analog Input/Output DAQ on PC/104

Model# of InputsResSpeed Bip RngUni RngAutocalFIFO# DACshf:att:pa_inputshf:att:pa_res-inputhf:att:pa_speedhf:att:pa_bip-rg-inputhf:att:pa_uni-rg-inputhf:att:pa_autocalhf:att:pa_fifohf:att:pa_outputs
104-AI12-8812100kHz22NoNoShow details812100khz22nono634
104-AIO12-8812100kHz22NoNo4Show details812100khz22nono4
104-AIO16A16 SE, 8 DIF16500kHz62RefsYes2Show details16-se-8-dif16500khz62refsyes2
104-AIO16E16 SE, 8 DIF16250kHz62RefsYes2Show details16-se-8-dif16250khz62refsyes2
104-AIM-32A32 SE, 16 DIF12100kHz6NoNoShow details32-se-16-dif12100khz6550nono
104-AIM-3232 SE, 16 DIF6NoNoShow details32-se-16-dif6376386550nono

Multifunction Analog Input/Output DAQ on REMOTE ACCES

Model# of InputsResSpeed Bip RngUni RngAutocalFIFO# DACshf:att:pa_inputshf:att:pa_res-inputhf:att:pa_speedhf:att:pa_bip-rg-inputhf:att:pa_uni-rg-inputhf:att:pa_autocalhf:att:pa_fifohf:att:pa_outputs
RIDACSShow details
RAD242Show details