Siemens Simatic S7 Series System Manual

Open loop motion control
12.6 Subroutines created by the Motion wizard for the Axis of Motion
S7-200 SMART
520 System Manual, 09/2015, A5E03822230-AC
12.6.13
AXISx_RDPOS subroutine
Table 12- 28 AXISx_RDPOS
LAD / FBD
STL
Description
CALL AXISx_RDPOS,
Error, I_Pos
The AXISx_RDPOS subroutine returns the current motion axis position.
Table 12- 29 Parameters for the AXISx_RDPOS subroutine
Inputs/Outputs
Data type
Operands
Error
BYTE
IB, QB, VB, MB, SMB, SB, LB, AC, *VD, *AC, *LD
I_Pos
DINT, REAL
ID, QD, VD, MD, SMD, SD, LD, AC, *VD, *AC, *LD
Turn on the EN bit to enable the subroutine.
The Error parameter (Page 545) contains the result of this subroutine.
The I_Pos parameter contains the current motion axis position.
Note
Execution of this command returns the actual current position of the axis. Position status
values provided in other motion subroutines, such as AXISx_CTRL, AXISx_GOTO, and so
forth,
are updated periodically. Therefore, the position values reported by those commands
and the position value reported by this command may differ somewhat as a result and is
normal.

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.