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1000 Series Squirrel

Eltek 1000 Series Squirrel data loggers provide a flexible combination of channels, ranges, memory sizes and extra options. If there is not already a model which fits a particular application, then Eltek can almost certainly make one.

Modular construction

Modular design

The basic element of the Squirrel data logger consists of the main board and the battery pack. The main board contains the power connector, display, RS232 serial connection, a pulse input, an 8 bit digital signal input and output connector. Up to eight additional input modules are connected to the main board during manufacture depending on the sensor input requirements.


Example Models

The following 1000 series Squirrels are examples of models from the range:

1063 Model
(24 Voltage/Current +
24 Thermocouple)
1067 Model
(48 Voltage/Current)
99 Channel model
(48 Voltage/Current
+ 48 PT100)


  • Battery or mains operated and easily portable
  • Configuration and Metering by:
         Panel controls and display
         Locally connected PC using Darca Software
         Remotely connected PC (using Darca Software) via GSM, landline or radio modem
  • Measure up to 250 analogue or digital channels, such as temperature, humidity, pressure, voltage, resistance, current or any other suitable sensor output
  • Non volatile internal memory providing up to 2 million readings of secure data
  • Readings can be scaled into appropriate units (e.g. m/sec, p.p.m.)
  • Low power consumption for long term unattended use or portable operation
  • Customised firmware for specialised requirements
  • LAN Network adaptor for Ethernet connection
  • Highly accurate: ±(0.1% of reading, +0.2% of range span)
  • 12 bit resolution
  • Sensor power outputs
  • 1 pulse count channel and 8 event/digital channels in addition to other inputs
  • External triggers can start and stop the logger
  • Rapid memory download at 38400 baud
  • Up to 99 logging "runs" may be stored
  • 3 year guarantee

Squirrel Modules

Each Squirrel Datalogger typically contains one CPU module and at least one input module. The CPU module contains two inputs of its own; one event input and one pulse input. Up to 8 input modules can be combined into one Squirrel Datalogger, for a maximum total of 250 input channels.

Which modules are available?

The following table shows each module and its input configuration. Click on the module name for a more detailed description.


Number of channels and type of input

Module U K/T P V/C P or V/C AC U / AC pH Co B F D Sensor Power Total channels
CPU 1 1x8* 2
M01 4 4 4 8
M01A 2 4+2V 4 8
M01B 6 2 2 8
M02 8 8
M16U 16 16
M03 4 4 4 8
M05 8 8
M25 16 16
M04 8 8
M06 2 2 4 6 8
M07 8 4 8
M11A 4 4 4 8
M11B 4 2 4 6
M10 6 2 8
M10C 3+3 2 8
M12A 4 4
M12B 8 8
M08 8 8
M28A 8 8
M28B 16 16
M09A 3x8* 3
M09B 8x8* 8
M27 16 x Relay Input Module 16

Key to Input Types:

U Thermistor Type U
K/T Thermocouple type K or T
P Platinum Resistance PT100
V/C Voltage or Current
AC AC Voltage or Current
pH pH
Co Conductivity
B Pulse Count
F Frequency
D Event / Digital

OPTIONAL MODULES FOR USE WITH THE CPU ONLY: (No additional height added)

Note: the CPU is provided with 1 x B input as standard
One only of the following modules can be added to the CPU.

MXP - Adds 1 additional B input (100 Hz Maximum)
MF2 - Adds 2 additional F inputs (standard 1 x B input forfeited)
MF3 - Adds 3 additional F inputs (standard 1 x B input forfeited)
MC - Adds PCcard slot for SRAM memory card

The Squirrel enables cost effective direct connection to a whole range of sensor types including temperature, humidity, and pH with options for pulse, frequency and digital inputs (Ideal for logging contact closures, shaft rotation and digital output form a weighing scale respectively).

There are also inputs available for measuring voltage and current (both AC and DC) .

Common Squirrel sensor types:

We can supply various types of probes for the above measurements.

If the sensor or probe for your application is not listed please do not hesitate to contact us as we may already have met and solved a similar problem. We are therefore well placed to recommend a solution or point you to a suitable supplier of probes.


Extra Memory

Extra memory is available for the Squirrel in the following sizes:

  • 520,000 Readings
  • 1,040,000 Readings
  • 2,080,000 Readings

One module only may be fitted to a Squirrel. Eltek loggers now download at 38400 baud, and in practice this is about 1000 readings per second.

Faster Logging

The Squirrel normally has a minimum logging interval of one second and can record up to 10 analogue channels per second. For faster logging, special Squirrels are available which can measure up to 8 channels with a minimum logging interval of 0.1sec. This option is currently not available on all loggers but is being constantly updated.

SMS Alarm nofitication

Eltek has implemented firmware for the 1000 Series Squirrels which will send a text message to up to 10 telephone numbers using the GSM-mdm modem option. See TU1016 - Using a GSMSQ modem with Squirrel data loggers for more details.



Logging Modes
Interval / average / event / externally triggered

Log / Scan Interval
1 sec to 24 hours
Optional: 0.1 sec minimum

Analogue Inputs
Accuracy: ±(0.1% of reading, +0.2% of range span)
Common mode range: 15V
Input Impedance: 1MW

Sensor Excitation
5V / supply voltage - internally selectable
Digital Inputs
0 / 5V or volt free contacts
8 inputs per logger channel

Pulse counters
Each counter up to 2KHz signal or 100Hz volt free contact. A total of 650K counts software selectable

Data memory
Internal memory: 250,000 readings
Option: 2 million readings or PC slot with SRAM card (2 million readings)
Memory modes: stop when full or continuous

Scaling Data
Readings scaled as engineering units

Panel controls and display and/or Darca Lite or Darca Plus (PC Software)

2 line, 32-character display for local status monitoring, configuration and stored readings

RS232 half duplex - 2400 to 38.4K Baud
Modem compatible protocol

Darca Software
Darca Lite for control, download and export
Darca Plus with graphing and analysis tools

Power supply
Internal: 6 x AA Alkaline batteries
External: 9 to 14 VDC (1.4 watts)
Mains adapter: 12 VDC 6 watts
Battery Life: sampling 8 channels every 5 minutes provides typically 6 months operation

Scratch resistant Nextel coated ABS
width 180mm, height 120mm,
depth - see table below

Operating Environment
Temperature range:-30 to 65°C
Humidity: 95% non condensing.
For harsh environments an optional IP67 enclosure is available


Product datasheet:
1000 Series Squirrel Leaflet

Product manual:
1000 Series Manual