Siemens Simatic S7 Series System Manual

Program instructions
7.6 Counters
S7-200 SMART
System Manual, 09/2015, A5E03822230-AC
227
HDEF instruction sets the counting mode
The HDEF instruction assigns HSC counter mode. The following table shows the physical
inputs assigned for clock, direction control, and reset functions. The same input cannot be
used for two different functions, but any input not being used by the present mode of its high-
speed counter can be used for another purpose. For example, if HSC0 is used in mode 1,
which uses I0.0 and I0.4; then I0.1, I0.2, and I0.3 can be used for edge interrupts, HSC3, or
motion control inputs.
Note
All counting modes of HSC0 always use I0.0 and all modes of HSC2 always use I0.2, so
these inputs
are never available for other uses when these counters are in use.
Mode
Description
Input assignment
HSC0
I0.0
I0.1
I0.4
HSC1
I0.1
HSC2
I0.2
I0.3
I0.5
HSC3
I0.3
0
Single-phase counter with internal direction
control
Clock
1
Clock
Reset
3
Single-phase counter with external direction
control
Clock
Direction
4
Clock
Direction
Reset
6
Two-phase counter with 2 clock inputs
Clock Up
Clock Down
7
Clock Up
Clock Down
Reset
9
AB quadrature phase counter
Clock A
Clock B
10
Clock A
Clock B
Reset

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.