852
APPX
Appendix 5  List of Special Register Areas
*1 There are restrictions on the firmware version of the supported CPU module and software version of the engineering tool. ( Page 
1008 Added and Enhanced Functions)
SD530 Scan program 
execution time
Scan program 
execution time (unit: 
ms)
• The execution time of the scan program for one scan is stored 
into SD530 and SD531 (it is measured in increments of s).
SD530: stores a value in the ms place (storage range: 0 to 65535)
SD531: stores a value in the s place (storage range: 0 to 999)
• These areas are cleared to 0 when the operating status of the 
CPU module is switched from STOP to RUN.
• In a redundant system, when the operating status of the CPU 
module is RUN state, these areas are cleared to 0 at the system 
switching.
S (Every END) ALL
SD531 Scan program 
execution time (unit: 
s)
ALL
No. Name Data stored Details Set by 
(setting 
timing)
CPU