Squirrel FAQs
Battery and Power
How long will the batteries last in the 2020/240 Logger?
With all channels logging, the following table can be used as a guide:-
| LOGGING INTERVAL |
1F8 |
2F8/2F16 |
4F16 |
| CONTINUOUS |
1.75 days |
1.25 days |
0.75 days |
| 5 seconds |
2.5 days |
2 days |
1.25 days |
| 10 seconds |
5 days |
3.75 days |
2.5 days |
| 15 seconds |
8 days |
6 days |
4 days |
| 30 seconds |
16 days |
12 days |
8 days |
| 1 minute |
25 days |
19 days |
12 days |
| 5 minutes |
75 days |
58 days |
37 days |
| 15 minutes |
120 days |
92 days |
62 days |
What happens when the batteries are exhausted?
It is not possible to arm the logger when below approximately 5.5. Volts. If the unit was logging when the voltage dropped below this point, it will disarm automatically.
Can I power from external supply?
Yes, 10-18V DC only. Includes 12V DC battery.What happens if the external supply fails? If the external power fails, batteries must be fitted to prevent loss of data. In the case of a power failure, the logger will switch to the battery supply and continue with no interruption.
How is the battery level displayed?
By use of a “bar” multi-segment battery indicator on the logger display and, if required, the actual voltage is displayed in the appropriate screen both on the logger display and in SquirrelView.
Can the 20xx Logger be used on a vehicle?
The logger is designed to be powered from a 12V vehicle system directly, higher system voltages will require the use of a suitable convertor. Two high voltage inputs are available to directly monitor vehicle supplies (up to 60V).
Can the Logger be powered by the USB port?
No. However, the use of USB does not put any extra load on the logger power supply or batteries.
How do I power a GSM modem?
A power adaptor lead is included with the GSM kit (SQ20A802) to power the modem and the Squirrel from the mains power pack (MPU-12V)
Can I power sensors from the Logger?
Yes Via connection terminal EA external supply (as supplied into the DC power socket Max 100mA B 5V regulated output Max 50mA
Can the internal batteries be rechargeable?
No only AA alkaline batteries should be used
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Connections and Communications
Is the Logger USB 2.0 Compliant?
Yes
Can I connect to the logger remotely?
Yes via 3rd party Ethernet or wireless adapters as well GSM and dial-up modem.
Contact Grant Instruments or your distributor for more details.
Is the logger real ‘plug & play’ via USB?
Windows will automatically detect the presence of your data logger, supplied drivers will be required the first time used.
What if I connect to both ports simultaneously?
The USB and serial ports may be physically connected at the same time; however, the logger will talk to only one external host at a time.
Can the logger survive mains supply accidentally connected to inputs?
The unit is not designed to withstand such an event; however the unit is ESD protected.
Can the Logger connect to Ethernet?
Yes the SQ2020 2F8, SQ2040 2F16 and the SQ2040 4F16 have inbuilt Ethernet connection. For the SQ2020 1F8 we supply a serial RS232, Ethernet converter kit (SQ20A801) a power adaptor lead is included with the kit to power the modem and the Squirrel from the mains power pack (MPU-12V)
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Operation
Can I download while the logger is logging?
Yes if downloaded via SquirrelView, but not to MMC. The logger will download until the point that the instruction to download was issued.
Can I download by time?
Yes, use the advanced function in the download screen.
What is the alarm output regime (one per channel)?
User specified triggers can activate a total of 4 alarm outputs. As an example; these triggers may be based upon channel conditions.
What can I trigger from?
Triggers can be from analogue, digital channels or time.
Can I print direct from the logger?
No, this can only be achieved via the host
Can I set an automatic download?
Yes Downloader is supplied on the SquirrelView CD
Why is the Ref Junction set automatically when I select a Thermocouple in
Sensor Type?
Thermocouples do not measure absolute temperature, they only measure the temperature difference between the sensing end (the probe tip) and the reference end (where the probe plugs into the logger). To acquire the absolute temperature the logger adds together the temperature difference measured by the thermocouple to the temperature at the reference junction. The reference junction temperature is measured by the Reference Junction channel. To save the user from having to remember to turn on the Reference Junction channel, SquirrelView and the logger do it automatically whenever a thermocouple channel is selected.
Can I use the logger outside?
The logger is not weatherproof if to be used outside or in damp conditions it will need to be placed in an IP rated enclosure
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General
Can I read my data using notepad (.csv file)?
By using SquirrelView you are able to export data to .csv format to a preferred spread sheet.
Can I fit the logger to a wall?
Yes, a universal bracket is supplied as standard with each Logger. It can be adjusted to act as a wall bracket or desk stand.
How often does the Logger require calibration?
Drift is not expected although annual calibration is recommended. In real terms this is dependant upon use. Contact Grant Instruments for further details. The last date of calibration can be viewed via SquirrelView->Diagnostics->20xx logger
What is the Inter-channel isolation?
For 1F8 loggers, inputs on blocks A to D share a common measurement circuit and must be within ±25V of each other and within ±60V of the negative pin on the logger’s power supply.
For 2F8 loggers, inputs on blocks A and B share one measurement circuit and blocks C and D share another measurement circuit. Inputs on blocks A and B must be within ±25V of each other and within ±60V of the negative pin on the logger’s power supply. Inputs on blocks C and D must be within ±25V of each other and within ±60V of the negative pin on the logger’s power supply. Inputs on blocks A and B must be within ±60V of the inputs on blocks C and D.
For 2F16 loggers, inputs on blocks A to D share one measurement circuit and blocks G to K share another measurement circuit. Inputs on blocks A to D must be within ±25V of each other and within ±60V of the negative pin on the logger’s power supply. Inputs on blocks G to K must be within ±25V of each other and within ±60V of the negative pin on the logger’s power supply. Inputs on blocks A to D must be within ±60V of the inputs on blocks G to K.
For 4F16 loggers, there are four separate measurement circuits connected to four pairs of input blocks - A and B, C and D, G and H, and J and K. Inputs on each pair of blocks must be within ±25V of each other and within ±60V of the negative pin on the logger’s power supply. Any input on any block pair must also be within ±60V of any other input on any other block pair.
Caution: Voltages approaching 60V and above can cause personal injury.
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Memory
How long will the memory last?
How long the memory will last is mainly dependant upon the number of channels set and their sample rate. For sample rates that are not sub-hertz, 16 bytes are used per reading (less than 16 bytes is used when logging sub-hertz). If Channel 1 was logging every second it would take approximately 11 days to fill the internal capacity or 16 weeks if logging every 10 seconds. If 4 channels log every 10 seconds the memory would fill in approximately 40 days.
The below table can be taken as a guide for a logger set to the default memory size of 16Mb
| Logging Interval |
1 Channel |
4 Channels |
8 Channels |
16 Channels |
32 Channels |
| 100 Samples Per Second * |
5 Hours |
1 Hour |
|
|
|
| 20 Samples Per Second * |
26 Hours |
7 Hours |
|
|
|
| 10 Samples Per Second * |
50 Hours |
13 Hours |
7 Hours |
|
|
| 5 Samples Per Second * |
92 Hours |
26 Hours |
13 Hours |
7 Hours |
|
| 2 Samples Per Second * |
184 Hours |
61 Hours |
32 Hours |
17 Hours |
8 Hours |
| 1 Second |
276 Hours |
110 Hours |
61 Hours |
32 Hours |
17 Hours |
| 15 Seconds |
4133 Hours |
1653 Hours |
919 Hours |
486 Hours |
251 Hours |
| 30 Seconds |
8267 Hours |
3307 Hours |
1837 Hours |
973 Hours |
501 Hours |
| 1 Minute |
16533 Hours |
6613 Hours |
3674 Hours |
1945 Hours |
1002 Hours |
* Refer to the logger sample rates for the number of channels possible at the faster sampling rates
If I install a external memory card, will it increase the memory?
No, the memory card is used to download your data without the need for a PC.
What happens when the memory is full?The logger will disarm and go into the memory full condition. The logger cannot be armed again until enough free space is made available by the deletion of data. Download and most other functions will still be available when memory is full.
Can I choose how much memory to download?
It is not possible to specify memory but it is possible to download between two specified times.
Do I need to use a specific brand of memory card?If you experiencing compatibility problems with a MMC/SD card, ensure that the logger controller firmware is at version 2.2 or above (firmware upgrades are included in you SquirrelView installation directory).
Do you recommend a specific brand of memory card reader?Any brand name should work without issue but SANDISK or Microtech Zio are two known good readers.
Can I program the logger from a memory card?Yes, in that setups created in SquirrelView can be saved onto a card and loaded into the logger using the stored setups menu.
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Speed
How fast can I log with n number of channels?
See Sample Rates under 2020/40 Squirrel
Can I have different channels logging at different speeds?Yes, a total of 4 sample intervals can be specified, but they must be multiples of each other.
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Front Panel Controls
How many channels can I view on the loggers display at the same time?
One channel at a time by using the metering feature, with auto scroll of all channels if required (press and hold enter key).
Can I display sampled inputs in real time?The metering feature allows data to be viewed on the logger display or SquirrelView at approximately 1Hz, regardless of channel sample rates.
Can you lock and disable the keypad?You can configure the logger such that no changes to setup can be made (read only). Refer to the Configuration Tab in SquirrelView Logger Setup.
Can I program the Logger from front panel?You may load pre-configured set-ups that have previously been stored in the logger, or from the External Memory Card
Can I start logging from the front panel key pad?Yes the logger can be armed and disarmed from the front panel key pad.
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