Hello,
first of all, I wish you a happy new year 2021.
I am a new user of a CR300.
I power the CR300 through an external power supply (24VDC). I would like to issue an alert when the external power is lost. Is it possible to read the voltage across the CHG terminal ? An other idea ? Thanks in advance,
Nicolas
Hi
do you not have a battery?
smile
Hi,
than you for your feedback. yes, I use a battery, I wanted to stop the measurements (and transmission) in the event of a power cut (to prevent the battery from discharging too much and that gives me time to resolve the problem)
thx
Nicolas
However you could use a resistor pair to make a divider and reduce the 24V to 5V and then through an analog channel, measure the recharge voltage.
Or simply even power a relay with 24V and use the normally open contact and use a digital port or analog channel and as long as the contact is closed the 24V are present.
Then with "if" programm activate an allarm
Smile
Hello, sorry for the late return but my posts remain "under review" for a long time. Yes, that's what I thought I would do if I couldn't find a "software" solution, which doesn't seem to exist.
A big thank you for your return.
Have a good day,
Nicolas
if you want to do a sw only check, it might be quite certain, see the battery voltage ONLY starts to drop, this happens if the charger does not charge.
Usually under charge the battery voltage is 13.8 ... 14V or more, while without charger it soon drops by at least half a volt and then slowly only begins to go down.
Obviously "slowly" depends on what powers the battery and how much its capacity is.
Smile
Does cellular communications work through the USB port? as the battery does not have to be on continuous charge, I could use a 12V to 5V converter and power through the USB port ... VBatt would drop to 5V ...
Nicolas
Hi
cellular connection through the USB port? never read anything about it. I believe the USB port is specific for PC connection which has drivers, a modem cannot. Moreover, the modem and the logger are 2 devices that interface to the PC and therefore cannot talk to each other.
Hello,
With only power supply via USB connector the cellular modem is effectively not active.
thank you for your advice
Nicolas
hello smile
we need the same solution, we need to measure CHG voltage on cR310 data logger, to avoid data loss.
We have a 12V7Ah battery and we charge the datalogger with a 24V power supply, but we want to know when the power supply fails and the datalogger is using the battery, to quickly repair the fault while the datalogger is powered by the battery, and not lose data with battery discharge.
we have revised the functions in crbasic to use the Voltdiff function, for example for diff channel 1
VoltDiff(DiffVolt,1,mV2500,1,True,4000,60,0.0,0)
But, we don't know how to make the physical connection on the channel.
We want to use the 1k/120 resistor divider to step down 24V to 2.4V.
Could you help us, how to make the connection in the datalogger?
Thanks.
This post is under review.
From my experience when the battery is being charged, the voltage is ~13.3V, approximately 1 hour after charging stops the voltage drops to ~12.8V.
You can set an alert to notify you when battery voltage is <13V.