SBC PCD1 Series Manual page 68

Saia-Burgess Controls AG
Storing a text/DB on the flash card, SYSWR K 9000
Instruction:
Accu status after execution:
When using the instruction SYSWR K 9000, note the following:
● The flash card can be written to a maximum of 100'000 times, so it is not permis-
sible to invoke the instruction in a cyclical manner or at short intervals
● A SYSRD K 9000 must be executed before this instruction, to test whether the
flash card is available and ready
● the processing time for the instruction may be up to 100 ms. At that point, there is
no guarantee that all of the text/DB has been written (the process will continue in
background). For this reason, the instruction must not be invoked in XOB 0 (XOB
for a power outage) or during time-critical processes
● if errors occur during processing, e.g. because no flash card is plugged in, XOB 13
will be invoked (where present), or the Error LED will be set
● when starting the Saia PCD
DBs after the last download is restored, even where the SYSWR K 9000 instruc-
tion has been used to store newer versions.
● Within the maximum number of write cycles, a text/DB can be stored any number
of times, without the flash card becoming over-full.
Manual Manual PCD 1 / PCD 2 Series │ D ocument 26 / 737 EN22 │ 2 013-11-26
SYSWR K 9000
1)
K number
1) Alternatively, the value 9000 can be passed in a register. On the PCD3, the instruction
SYSWR K 3000 is used for the same function. For reasons of compatibility, SYSWR
K 3000 can also be used on the PCD1/2, but this alternative was only integrated into the
firmware in the 2nd half of 2004
low: the text/DB has been saved, and the flash card is ready
for new SYSWR instructions
high: the last instruction was not processed to completion;
before further SYSWR K 900x instructions, a SYSRD
K 9000 must be executed to check the readiness of the
flash card
after a loss of RAM memory, the state of the texts/
®
CPUs and expansion housings
; address of the texts/DBs as
; K constant or in a
; register, existing text/DB addresses in
; the range >= 4000 may be used
Backup of the user program
3
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