Saia-Burgess Controls AG
Hardware manual for PCD3 series │ Document 26-789 ENG19│ 2018-06-29
Storage space on the PCD3
PCD3.Mxxx0 Classic CPU and expansion enclosure
3-51
3
TheμSDashcardonthesystemboardmustnotberemovedunder
anycircumstances(itincludesthermwareetc.)!
The Saia PCD3 Plus automation devices (red type plate,
PCD3.Mxx60)areequippedwithanonboardμSDashcard.
When loading a user application with Saia PG5
®
, all the
necessarylesarestoredontheμSDcard.
If the operating voltage is connected to the automation device
and there is no executable program in the user memory,
COSinusattemptstoloadavalidprogramfromtheμSDash
card into the main memory on startup.
Saia P
CD3.Mxx6x
Loading of the user program from PG5® onto Saia PCD® auto-
mation devices and allocation of dierent data between the
storage media.
SRAM
Media (R, T, F)
PCD3.Mxx6x
File system
SRAM data
User program
RIO application
load as required
RAM
μSD ash card
secure on demand (backup)
User memory= RAM text/DB memory
In these systems, the RAM (Random Access Memory) includes text and DB
memoryaswellasthemedia(R,T,F).TheaddressoftherstRAMtext/DBisset
in the PG5 build options.
All texts and DBs have a maximum size of 16383 elements (DBs) respectively
65535 bytes.
ROM text/DB cannot be written to the PCD3 power CPUs, whereas it was still
possible on earlier systems. The program is always loaded on these systems on
ashinthePCDandisthereforealwaysavailableevenifthereisnobatteryThe
programisalwaysloadedonthesesystemsonashinthePCDandistherefore
always available even if there is no battery.