Hi,
yes there's is a single 3V lithium battery inside the cFP 2120.
Usually you'd hook up to a time server to handle for any time slipages, or just to make sure that all the units on the network are working from the same timestamp, but if you don't want this, then set the time-server to 0.0.0.0. (You can use this to prove whether the battery is keeping the time by setting it to 0.0.0.0, then run some code to write a file (it will be timestamped, or but the current time into the text of the file) and then switch it off for a couple of minutes. On power up, check the time again.)
Hope that helps
Sacha Emery
National Instruments (UK)
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