SNAP Analog Input Modules

Opto 22 • 43044 Business Park Drive • Temecula, CA 92590-3614 • www.opto22.com

SALES 800-321-6786 • 951-695-3000 • FAX 951-695-3095 • sales@opto22.com • SUPPORT 800-835-6786 • 951-695-3080 • FAX 951-695-3017 • support@opto22.com

© 2001–2014 Opto 22. All rights reserved. Dimensions and specifications are subject to change. Brand or product names used herein are trademarks or registered trademarks of their respective companies or organizations.

SNAP Analog Input Modules

DATA SHEET

Form 1065-140815

PAGE

Thermistor Input Module 0–40 K, 0–20 K, 0–10 K, or 0–5 K Ohm

Specifications

SNAP-AIR40K-4

IMPORTANT: The mounting rack connector has 24 pins; the module

connector has 20 pins. The extra pins on the mounting rack

connector prevent misalignment of the module during installation.

Description

The SNAP-AIR40K-4 module provides four channels of analog

to digital conversion, ideal for thermistors used in HVAC

applications or for reading the resistance of potentiometer

input. See the table on page 3 for I/O processor compatibility.

The default input range is 0 to 40 K Ohms. The module can

also be configured for 0 to 20 K, 0 to 10 K, or 0 to 5 K Ohms.

NOTE: Resistance probes must be isolated from each other.

Part Number Description

SNAP-AIR40K-4

Four-channel analog resistor/thermistor

input, 40 K Ohms, 20 K Ohms, 10 K Ohms,

or 5 K Ohms

Input Range

0 to 40,000 Ohms

0 to 20,000 Ohms

0 to 10,000 Ohms

0 to 5,000 Ohms

Maximum Over-Range

44 K (40 K Ohms range)

22 K (20 K Ohms range)

11 K (10 K Ohms range)

5.5 K (5 K Ohms range)

Resolution

1.6 Ohm @ 40 K Ohms

0.8 Ohm @ 20 K Ohms

0.4 Ohm @ 10 K Ohms

0.2 Ohm @ 5 K Ohms

Input Filtering -3 dB @ 3.2 Hz

Data Freshness (Max)

100 (40 K Ohms)

200 (20 K Ohms)

400 (10 K Ohms)

800 (5 K Ohms)

DC Common Mode Rejec-

tion

>-120 dB

AC Common Mode Rejec-

tion

>-120 dB @ 60 Hz

Maximum Operating Com-

mon Mode Voltage

250 V

Accuracy

0.1% ± 40 Ohms @ 40 K Ohms

0.1% ± 20 Ohms @ 20 K Ohms

0.1% ± 10 Ohms @ 10 K Ohms

0.1% ± 5 Ohms @ 5 K Ohms

DRIFT: Gain Temperature

Coefficient

30 PPM/ °C

DRIFT: Offset Tempera-

ture Coefficient

15 PPM/ °C

Isolation 1500 V

Power Requirements 5 VDC (±0.15 ) @ 190 mA

Operating Temperature 0 °C to 70 °C

Storage Temperature -40 °C to 85 °C

Wire size 22 to 14 AWG

Torque, hold-down screws 4 in-lb (0.45 N-m)

Torque, connector screws 5.26 in-lb (0.6 N-m)

Agency Approvals UL, FM, CE, RoHS, DFARS

Warranty Lifetime

SNAP Analog Input Modules

Opto 22 • 43044 Business Park Drive • Temecula, CA 92590-3614 • www.opto22.com

SALES 800-321-6786 • 951-695-3000 • FAX 951-695-3095 • sales@opto22.com • SUPPORT 800-835-6786 • 951-695-3080 • FAX 951-695-3017 • support@opto22.com

SNAP Analog Input Modules

PAGE

DATA SHEET

Form 1065-140815

Thermistor Input Module 0–400 K, 0–200 K,

0–100 K, 0–50 K, 0–40 K, 0–20 K, 0–10 K,

0–5 K, 0–4 K, 0–2 K, 0–1 K, 0–500 Ohm

SNAP-AIR400K-8

IMPORTANT: The mounting rack connector has 24 pins; the module

connector has 20 pins. The extra pins on the mounting rack

connector prevent misalignment of the module during installation.

Description

The SNAP-AIR400K-8 module has eight channels of analog to

digital conversion that convert resistance to temperature or to

Ohms. The module is ideal for NTC thermisters commonly used

in HVAC, refrigeration, and process control applications. It may

also be used with PTC thermisters in resistance sensing

applications. See the table on

page 3

for I/O processor

compatibility.

NTC thermistor

Variable resistance device

Part Number Description

SNAP-AIR400K-8

Eight channel analog resistor/thermistor

input, 400 K Ohms, 200 K Ohms,

100 K Ohms, 50 K Ohms, 40 K Ohms,

20 K Ohms, 10 K Ohms, 5 K Ohms,

4 K Ohms, 2 K Ohms, 1 K Ohms, 500 Ohms

The SNAP-AIR400K-8 reads variable resistance type

transducers, and it has 12 resistance input ranges from 500

Ohms to 400 K Ohms, plus Autorange. Range dependent

resolution is from 20 milliOhms to 16 Ohms.

SNAP PAC brains and PAC Control provide direct temperature

readings for four popular thermistors using the Steinhart-Hart

equation (see page 16). You may also enter custom

coefficients for unsupported thermistor curves.

The simple two-wire connections are made to the pluggable

terminal strip on top of the module.

NOTE: The eight input channels must be electrically isolated from

each other and earth ground. The transducer resistor element

must be isolated from any electrically conducting probe tube

housing.

See page 15 for module specifications.

Wiring Information

Unshielded 24 AWG wire (minimum) is recommended.

SNAP Analog Input Modules

Opto 22 • 43044 Business Park Drive • Temecula, CA 92590-3614 • www.opto22.com

SALES 800-321-6786 • 951-695-3000 • FAX 951-695-3095 • sales@opto22.com • SUPPORT 800-835-6786 • 951-695-3080 • FAX 951-695-3017 • support@opto22.com

SNAP Analog Input Modules

DATA SHEET

Form 1065-140815

PAGE

Thermistor Input Module 0–400 K (continued)

Specifications

Input Ranges

400 K, 200 K, 100 K, 50 K, 40 K, 20 K, 10 K, 5 K , 4 K, 2 K, 1 K, 500

Ohms, and Autorange

Fixed Range Overrange Limits

(Ohms Resolution)

440 K (16), 220 K (8), 110 K (4), 55 K (2), 44 K (1.6), 22 K (0.8), 11 K

(0.4), 5.5 K (0.2), 4.4 K (0.16), 2.2 K (0.08), 1.1 K (0.04), 550 (0.02)

Data Freshness 1.61 seconds maximum

DSP Notch Filter 20 Hz (- 3DB = 5.24 Hz)

Excitation Current Nominal (Range & Load

Watts Dissipation)

9uA (50 K–4.1 uW), (100 K–8.1 uW), (200 K–16 uW), (400 K–32 uW)

90uA (5 K–40 uW), (10 K–81 uW), (20 K–160 uW), (40 K–320 uW)

200uA (500 K–20 uW), (1 K–40 uW), (2 K–80 uW), (4 K–160 uW)

Autorange Step Time

1.6 seconds to next higher or lower range

>= 10 seconds for a 500 Ohms to 400 K Ohms step change

Autorange Ohms Hysteresis

Ranges

Ohms Open > 440K

20K between 200K & 400K

10K between 100K & 200K

5K between 50K & 100K

19K between 40K & 50K

2K between 20K & 40K

1K between 10K & 20K

500 between 5K & 10K

1.9K between 4K & 5K

200 between 2K & 4K

100 between 1K & 2K

50 between 500 & 1K

DC Common Mode Rejection

>-120 dB

AC Common Mode Rejection

>-120 dB @ 60 Hz

Open Resistor Indicator Channel resistence = 999,999.999

PAC Control Reads temperature reading or -32768 Ohms if over or under range

Maximum Operating Common Mode Voltage

(Field Term to Logic Connector)

500 VDC or peak VAC

Accuracy

(Ohms @ Range)

0.1% Reading

+ 2x Range Resolution

+ 1 Ohm

4 Ohms @ 4 K

2 Ohms @ 2 K

1 Ohms @ 1 K

0.5 Ohms @ 500

40 Ohms @ 40 K

20 Ohms @ 20 K

10 Ohms @ 10 K

5 Ohms @ 5 K

400 Ohms @ 400 K

200 Ohms @ 200 K

100 Ohms @ 100 K

0 Ohms @ 50 K

Drift

Gain Tempco

Offset Tempco

30 PPM / °C

15 PPM / °C

Power Requirements 5 VDC (±0.15 ) @ 190 mA

Operating Temperature 0 °C to 70 °C

Storage Temperature -40 °C to 85 °C

Torque, hold-down screws 4 in-lb (0.45 N-m)

Torque, connector screws 5.26 in-lb (0.6 N-m)

Agency Approvals UL (pending), CE (pending)

Warranty Lifetime

Part #	SNAP-AIRATE
Description	I/O MODULE, Current Rating:-,Accessory Type:Rate Input Mo
Category	MODULE
Availability	In Stock
Qty	1

SNAP-AIRATE

Related Items

Technical Document