Siemens SIMATIC S7-1200 Manual page 15

Table 1- 2 Blocks, timers and counters supported by S7-1200
Element
Blocks Type
Size
Quantity
Address range for FBs, FCs,
and DBs
Nesting depth
Monitoring
OBs Program cycle
Startup
Time-delay interrupts and
cyclic interrupts
Hardware interrupts (edges
and HSC)
Time error interrupts
Diagnostic error interrupts
Timers Type
Quantity
Storage
Counters Type
Quantity
Storage
Time-delay and cyclic interrupts use the same resources in the CPU. You can have only a total of 4 of these interrupts
1
(time-delay plus cyclic interrupts). You cannot have 4 time-delay interrupts and 4 cyclic interrupts.
Easy Book
Manual, 11/2011, A5E02486774-04
Introducing the powerful and flexible S7-1200
Description
OB, FB, FC, DB
25 Kbytes (CPU 1211C and CPU 1212C)
50 Kbytes (CPU 1214C)
Up to 1024 blocks total (OBs + FBs + FCs + DBs)
1 to 65535 (such as FB 1 to FB 65535)
16 from the program cycle or start up OB; 4 from the time delay
interrupt, time-of-day interrupt, cyclic interrupt, hardware interrupt,
time error interrupt, or diagnostic error interrupt OB
Status of 2 code blocks can be monitored simultaneously
Multiple: OB 1, OB 200 to OB 65535
Multiple: OB 100, OB 200 to OB 65535
4 (1 per event): OB 200 to OB 65535
1
50 (1 per event): OB 200 to OB 65535
1: OB 80
1: OB 82
IEC
Limited only by memory size
Structure in DB, 16 bytes per timer
IEC
Limited only by memory size
Structure in DB, size dependent upon count type
SInt, USInt: 3 bytes

Int, UInt: 6 bytes

DInt, UDInt: 12 bytes

1.1 Introducing the S7-1200 PLC
15