Hardware Manual

Hardware Manual PCD 1 / PCD 2 Series│Document 26 / 737│Edition EN 15│2008-07-22

Saia-Burgess Controls AG

Backup of the user program

CPUs and expansion housings

3

Deleting    stored  texts/DBs   on  the flash   card,   

SYSWR   K   9002

Instruction: SYSWR K 90021)

K 0 ; Dummy parameter, required to

; maintain the structure of the SYSWR

; instruction

1) Alternatively, the value 9002 can be passed in a register. On the PCD3, the instruction

SYSWR K 3002 is used for the same function. For reasons of compatibility, SYSWR K

3002 can also be used on the PCD1/2, but this alternative was only integrated into the

firmware in the 2nd half of 2004

Accu status after execution:

low: The text strings/DBs have been deleted and the process

is complete, so further SYSWR K 900x instructions can

be executed immediately

high: The last instruction has not yet processed to completion;

before further SYSWR K 900x instructions, a SYSRD

K 9000 must be executed to check the readiness of the

flash card

When using the instruction SYSWR K 9002, note the following:

 The deletion only affects text/DBs previously stored with SYSWR K 9000. The

contents of the extension memory stored after a download are retained

 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 several 100 ms. 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