Saia-Burgess Controls AG
Manual
Manual PCD 1 / PCD 2 Series
│ Document 26
/
737 E
N22 │ 2013-11-26
CPUs and expansion housings
3-46
Data storage in case of power outage
3
3.16
Data storage in case of power outage
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 PCD1/PCD2 are equipped with a buffer capacitor (SuperCap) or a buffer battery.
CPU type
Buffer
Buffer time
PCD1.M110
Super Cap (soldered)
30 days
1) 2)
PCD1.M120/M125
Super Cap (soldered)
7 days
2)
PCD1.M130/M135
CR 2032 lithium battery
1-3 years
3)
PCD2.M110/M120
hardware version < H
2 × alkaline batteries size
LR03/AAA/AM4/Micro
1-5 years
3)
PCD2.M110/M120
hardware version >= H
CR 2032 lithium battery
1-3 years
3)
PCD2.M150/M170/M480 CR 2032 lithium battery
1-3 years
3)
1) The PCD1.M110 has no hardware clock, so the buffer time is greater than it is for the PCD1.M120
2) The total load time of the PCD1.M110, PCD1.M120 and PCD1.M125 amounts to approx. 30 minutes
3) 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 comissioning. Observe the polarity of the batteries:
●
for alkaline batteries, the polarity can be seen on the socket
●
insert CR 2032 coin cell in such a way that the Plus pole is visible
CPUs with alkaline or 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 below 2.4 V
or above 3.5 V
●
the battery is flat or shows an interrupt
●
the battery is missing
We recommend changing the batteries with the Saia PCD
®
attached to the power
supply, to avoid any loss of data.
The batteries are easy to locate on all CPU types.
PCD1.M130:
PCD1.M135:
PCD2.M110/120/150: