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en:automation:02-glossary:analog-inputs-hidden [2018/09/04 06:55] mkudlacek |
en:automation:02-glossary:analog-inputs-hidden [2021/06/09 08:48] (current) avsetula |
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| ====== Analog inputs ====== | ====== Analog inputs ====== | ||
| - | Analog inputs (AI) are for reading DC voltage or DC current. The actual range is 0-10V or 0-20mA, which is an industrial standard. | + | Analog inputs (AI) are for measuring analog values such as DC voltage, current and resistance. These values are produced by sensors which indicate multiple states such as thermometers, tensometers, distance meters, lux meters etc. |
| - | The inputs are suitable for reading values from analog sensors such as temperature sensors, pressure meters, tensometers etc. | + | |
| - | <WRAP center round tip 60%> | + | ---- |
| - | On Neuron and Axon, the analog inputs can also measure resistance, making the AIs suitable for measuring temperature from resistive thermometers such as Pt100, Pt500, Pt1000 and Ni1000. | + | |
| - | </WRAP> | + | |
| - | ===== Analog inputs Neuron and Axon ===== | + | <html><span class="kbBlueText">More information about analog inputs can be found in specific categories:</span></html>\\ |
| - | The functionality of AIs on Neuron and Axon is different on Group 1 and Group 2/3 or Neuron extensions. | + | |
| - | On Group 1, the analog input is only capable of measuring DC voltage in a range of 0-10V and DC current in a range of 0-20mA. | + | <tile> |
| + | | en:hw:007-patron:description-of-io:04-description-of-ai | Patron | :en:hw:unipi-kb-icon-patron.png | | ||
| + | | en:hw:01-axon:description-of-io:04-description-of-ai | Axon | :en:hw:unipi-kb-icon-axon.png | | ||
| + | | en:hw:02-neuron:description-of-io:04-description-of-ai | Neuron | :en:hw:unipi-kb-icon-neuron.png | | ||
| + | | en:hw:03-unipi11:description-of-io:04-description-of-ai | 1.1 & 1.1 Lite | :en:hw:unipi-kb-icon-1.png | | ||
| + | | en:hw:04-extensions:description-of-io:04-description-of-ai | Extension modules | :en:hw:unipi-kb-icon-extension.png | | ||
| + | </tile> | ||
| - | On Group 2 and 3 and on the Neuron extensions, the analog input is capable of: | + | |
| + | /* | ||
| + | ===== Analog inputs on Neuron and Axon ===== | ||
| + | The functionality of AIs on Neuron and Axon is different on Group 1 and Group 2/3 and Neuron extensions. | ||
| + | |||
| + | On Group 1, the analog input is capable of: | ||
| + | * measuring 0-10V DC | ||
| + | * measuring 0-20mA DC | ||
| + | |||
| + | <WRAP center round tip 60%> | ||
| + | The Group 1 is also capable of measuring the resistance, but this is achievable with [[en:automation:02-glossary:analog-outputs-hidden|Analog output]]. | ||
| + | </WRAP> | ||
| + | |||
| + | On Group 2 and 3 and the Neuron extensions, the analog input is capable of: | ||
| * measuring 0-10V DC | * measuring 0-10V DC | ||
| * measuring 0-2.5V DC with higher precision | * measuring 0-2.5V DC with higher precision | ||
| * measuring of 0-20mA DC | * measuring of 0-20mA DC | ||
| - | * measuring of resistance 0-100kOhm via 2-wire method | + | * measuring of resistance 0-100kOhm via a 2-wire method |
| - | * measuring of resistance 0-2kOhm via more precise 3-wire method | + | * measuring of resistance 0-2kOhm via a more precise 3-wire method |
| + | |||
| + | Changing between modes depends on the [[en:sw:00-start|software]] you are using, please follow the relevant tutorial. | ||
| + | |||
| + | ==== Measuring voltage ==== | ||
| + | ==== Measuring current ==== | ||
| ===== Analog inputs on Unipi 1.1 ===== | ===== Analog inputs on Unipi 1.1 ===== | ||
| - | The UniPi 1.1 has two analog inputs and they are only capable of measuring voltage in a range of 0-10V DC. | + | The Unipi 1.1 has two analog inputs and they are only capable of measuring voltage in a range of 0-10V DC. |
| + | |||
| + | ==== Measuring resistance ==== | ||
| + | To measure resistance from the Unipi 1.1's AI (ie. by using PT1000 thermal probes), it is necessary to add a resistor according to the following scheme. | ||
| + | |||
| + | {{:en:automation:02-glossary:unipi_ai.png?300|}} | ||
| + | |||
| + | R_sens = the sensor itself | ||
| + | R_ref = the reference resistor | ||
| + | |||
| + | There is also a input resistor inside of the AI with the value: | ||
| + | |||
| + | R_ai = 12200ohm | ||
| + | |||
| + | <WRAP center round alert 60%> | ||
| + | For R_sens >= 200ohm, use R_ref = 1k. For R_sens < 200ohm, use R_ref = 10k | ||
| + | </WRAP> | ||
| + | |||
| + | The value at the AI is calculated from the voltage you read from the AI (V_ai) | ||
| + | Vcc - V_ai R_ref * R_ai | ||
| + | R_sens = ------------ * -------------- | ||
| + | V_ai R_ref + R_ai | ||
| + | | ||
| + | The Vcc is the applied voltage (12V in the picture above). | ||
| + | */ | ||
