Hardware Manual for the PCD2.M5 Series│Document 26/856; Version EN 12│2014-07-24
Saia-Burgess Controls AG
Changing the battery on the PCD2.M5xx0
Maintenance
9-1
9
9 Maintenance
PCD2 components are maintenance-free, apart from the CPUs, where the battery
needs to be changed occasionally.
PCD2 components do not contain any parts that can be swapped out by the user. If
hardware problems arise, the components should be returned to SBC.
9.1
Changing the battery on the PCD2.M5xx0
The resources (registers, flags, 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.M5xx0
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:
●
Insert CR 2032 coin cells in such a way that the Plus pole is visible
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
the battery voltage is less than 2.4 V
the battery is missing
We recommend changing the batteries with the PCD attached to the power supply, to
avoid any loss of data.