Siemens Simatic S7 Series System Manual

Program instructions
7.17 Timer
S7-200 SMART
System Manual, 09/2015, A5E03822230-AC
343
Example: automatically retriggered One-shot timers
The corrected examples use the normally closed contact Q0.0 instead of the timer bit as the
timer enabling input. This ensures that output Q0.0 is turned ON for one scan cycle, each
time a timer reaches the preset value.
1 ms timer
Q0.0 is turned ON for one scan whenever the timer's current value is updated after the
normally closed contact T32 is executed and before the normally open contact T32 is
executed.
10 ms timer
Q0.0 is never turned ON, because the timer bit T33 is turned ON from the top of the scan to
the point where the timer box is executed. Once the timer box has been executed, the
timer’s current value and its T–bit are set to zero. When the normally open contact T33 is
executed, T33 is OFF and Q0.0 is turned OFF.

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.