Siemens SINUMERIK 828D Function Manual page 957

PI service: MMCSEM
Semaphores for various PI services
For use by HMI and PLC
10 semaphores are provided for each channel. These protect critical functions for the HMI/PLC. By setting the
semaphore for the corresponding function number, several HMI/PLC units can be synchronized with it in cases
where a function contains a critical section with respect to data to be fetched by the NCK. Semaphores are
managed by the HMI/PLC. A semaphore value of 1stipulates a Test & Set operation for the semaphore of the
specified function number. The return value of the PI service represents the result of this operation:
• Checkback value Done := TRUE: Semaphore has been set, critical function can be called
• Checkback value Error := TRUE with state = 3: Semaphore was already set, critical function cannot be called
at the present time. The operation must be repeated later.
NOTICE
On completion of the operation (reading data of this PI service) it is essential that the
semaphore is enabled again.
Parameter:
WVar1 = FunctionNumber
This function number represents a PI service:
Function number
1
2
3
4
5
6
7 ... 10
WVar2=SemaphorValue
Value Meaning
0: Reset semaphore
1: Test and set semaphore
Parameterization
Signal
PIService
Unit
WVar1
WVar2
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
PI service
TMCRTO (create tool)
TMFDPL (search for empty location for loading):
TMMVTL (prepare magazine location for loading, unload tool)
TMFPBP (search for location)
TMGETT (search for tool number)
TSEARC (search for tool)
Reserved
Type
ANY
INT
INT
WORD
P3: Basic PLC Program for SINUMERIK 840D sl
Value range Meaning
PI.MMCSEM Set semaphore
1, 2 to 10 Channel
1 ... 10 FunctionNumber
0, 1 SemaphoreValue
13.13 Block descriptions
957