Siemens Simatic S7 Series System Manual

Program instructions
7.13 Program control
S7-200 SMART
System Manual, 09/2015, A5E03822230-AC
309
The divergence of control streams can be implemented in an SCR program by using multiple
SCRT instructions enabled by the same transition condition, as shown in the following
example.
Example: SCR divergent flow control
LAD
STL
Beginning of state L control re-
gion
Network 1
LSCR S3.4
S3.5: Transition to state M
S6.5: Transition to state N
Network 2
LD M2.3
A I2.1
SCRT S3.5
SCRT S6.5
End of the state region for state L
Network 3
SCRE
Convergent flow control
When streams converge, all incoming streams must be complete before the next state is
executed.
The convergence of control streams can be implemented in an SCR program by making the
transition from state L to state L' and by making the transition from state M to state M'. When
both SCR bits representing L' and M' are true, state N is enabled as shown in the following
example.

Siemens Simatic S7 Series Specifications

General

CPU	Varies by model (e.g., S7-300, S7-400, S7-1200, S7-1500)
Communication Interfaces	PROFIBUS, PROFINET, Ethernet, MPI
Programming	TIA Portal, STEP 7
Programming Languages	LAD, FBD, STL, SCL, GRAPH
I/O Modules	Digital, Analog, Specialty modules available
Operating Temperature	0°C to 60°C (standard models)
Mounting	DIN rail mounting
Operating Voltage	24V DC or 120/230V AC (varies by model)
Protection Class	IP20 (standard models)
Memory	Varies depending on the S7 model. Includes work memory (RAM) for program execution, load memory (EEPROM or Flash) for program storage, and system memory for operating system functions. Memory sizes range from kilobytes to megabytes.