I had forgotten that the cRio 9075 contoller/chassis doesn't have a battery backed RT clock.
We are about to start developing a system that will be powered down completely, then started up in the field from a battery bank. Anybody have any suggestions for a realtime clock we can use to set the internal clock on startup?
The 9075 chassis has a serial port we aren't using, but I haven't found any small clock units that have RS-232. I have seen several really cheap clock modules that use I2C comms.
Our NI-9381 Multifunction module has a 4bit LVTTL port, could we use that for I2C comms with a clock module? Anybody tried that?