Siemens SIMATIC NET S7-300 User Manual

7 Programming FCs (Functions) and FBs for S7 Ethernet CPs
A-213
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
7.4.2 FC8 AG_UNLOCK
Meaning of the Block
Using the AG_UNLOCK function, the external access to system areas on the S7
CPU with FETCH or WRITE on the connection specified by the ID parameter is
released.
The next external FETCH/WRITE job to arrive for the CP can then be processed.
The AG_UNLOCK follows an access lock with AG_LOCK.
Call
Call interface in FBD representation
LADDR
AG_UNLOCK
ID
STATUS
Example in STL representation
STL Explanation
call fc 8
ID := DB 100.DBW 2
LADDR := W#16#0100
STATUS := DB 100.DBW 4
//Block call
//Connection ID acc. to configuration
//=LADDR 256 dec. in hardware configuration
//Status code
How the Block Works
To release the connection again, the LOCK request bit must be cleared by the FC
again. The FC also shows the current status using error messages.
Explanation of the Formal Parameters
The following table explains all the formal parameters for the AG_UNLOCK
function:

Siemens SIMATIC NET S7-300 Specifications

General

Product Type Designation	SIMATIC NET S7-300
Mounting	DIN rail mounting
Protection Class	IP20
CPU Models	Various models available (e.g., CPU 312, CPU 314)
Communication Interfaces	MPI, PROFIBUS DP
Power Supply	24 V DC power supply required. Different power supply modules available.
I/O Modules	Digital input modules, digital output modules, analog input modules, analog output modules
Programming	STEP 7 software
Supply Voltage	24V DC or 120/230V AC (depending on model)
Digital Inputs	Available via digital input modules
Digital Outputs	Available via digital output modules
Analog Inputs	Available via analog input modules
Analog Outputs	Available via analog output modules
Communication Functions	MPI, PROFIBUS DP, Ethernet (depending on model)
Protocols	MPI, PROFIBUS DP, TCP/IP (depending on model)
Operating Temperature	0°C to 60°C
Storage Temperature	70 °C
Memory	Depends on CPU model (e.g., 32 KB to 1.5 MB)