Hardware Manual for the PCD3 Series│Document 26/789; Version E 5│31.01.2005
Saia-Burgess
Controls Ltd.
Changing the battery on the PCD3.Mxxx0
Maintenance
7-1
7
7
Maintenance
PCD3 components are maintenance-free, apart from some CPUs (PCD3.Mxxx0),
where the battery needs to be changed occasionally.
PCD3 components do not contain any parts that can be swapped out by the user. If
hardware problems arise, the components should be returned to Saia-Burgess.
7.1
Changing the battery on the PCD3.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 outage,
the PCD3s are equipped with a buffer capacitor (SuperCap) or a buffer battery.
CPU type
Buffer
Buffer time
PCD3.M3xx0
Super Cap (soldered)
8 hours
PCD3.M5xx0
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 2.4V or more than 3.5V
the battery is flat 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.
