SBC PCD2.M5 Series - Data Storage in Case of Power Failure; Battery Changing

Hardware Manual for the PCD2.M5 Series│Document 26/856; Version EN 12│2014-07-24
Saia-Burgess Controls AG
Data storage in case of power failure
PCD2.M5_ Classic CPUs and expansion housings
3-31
3
3.11 Datastorageincaseofpowerfailure
Theresources(registers,ags,timers,countersetc),andpossiblytheuserprogram
and the text strings/DBs, are stored in RAM. To ensure that they are not lost and that
thehardwareclock(wherepresent)continuestorunwhenthereisapowerfailure,
thePCD2sareequippedwithabuffercapacitor(SuperCap)orabufferbattery:
CPU type Buffer Buffer time
PCD2.M5_ Renata CR 2032 lithium battery 1...3 years
1)
1)
Dependingontheambienttemperature;thehigherthetemperature,theshorterthebuffertime
With new controllers, the batteries are packaged with the units, and have to be
inserted on commissioning. Observe the polarity of the batteries:
3.11.1 Batterychanging
● Remove PCD cover
● Pull locking clip in the direction of the embossed plus sign on
thehousing(seearrow)
● Remove old battery
● Insert new Renata CR2032 battery in such a way that the Plus
pole is in contact with the locking clip
CPUs with lithium batteries are not maintenance-free. The battery voltage is
monitoredbytheCPU.TheBATTLEDlightsupandXOB2iscalled(ifXOB2isnot
programmed,theERRORLEDwillalsolightupafter1secondofbatteryfailure),
where
 the battery voltage is less than 2.4 V
 thebatteryisatorshowsaninterrupt
 the battery is missing
We recommend changing the batteries with the PCD attached to the power supply, to
avoid any loss of data.