Siemens SPC3 Specifiche Scaricare il pdf (Pagina 27)

DPC31 HW

SchnittStellenCenter

DPC31 HW Description

Version V1.0 Page 25

The Din data is controlled via three exchange buffers of the same length. One buffer each is assigned to the

data transfer ‘D’ and the user ‘U’. The third buffer is either in a Next “N” mode, or Free ‘F’ mode. When

sending, the MAC fetches the Din data from ‘D’. The user prepares new Din data in ‘U’ and then moves it to

‘N’. DPS then changes the buffers from ‘N’ to ‘D’.

For the diagnostic SAP and the Get_Cfg SAP (SAP60/59), two buffers respectively are available that may

have different lengths. The 'D' buffer is always assigned to the MAC for sending and the 'U' buffer belongs to

the user for preparing new data. DPS exchanges the buffers upon user request.

In SAP55 (Set_Slave_Address), SAP61 (Set_Param), and SAP62 (Check_Config), one indication buffer

respectively is available, to which the received data is stored. At the indication, this buffer is exchanged for

the corresponding buffer in DPS buffer management (User_SSA buffer, User_Prm buffer, or User_Cfg

buffer) and then the corresponding DPS control unit is triggered.

5.2.1 Set_Slave_Address, SSA (SAP55)

Two exchange buffers of the same length are available for this SAP. One buffer is integrated as indication

buffer in the SAP_SCB (MAC_SSA buffer) and the other is included in DPS buffer management as

User_SSA buffer. The indication is always transferred to the user in User_SSA Buffer.

The user can disable the SSA service by setting the ‘MAC_SSA_Buffer Ptr=00h’ at power-up. The DPC31

then responds to an SSA request with ‘no service activated’.

The new ‘Station Address’ and the parameter ‘Real_No_Add_Change’ are stored by the user and

retransferred to the software modules “MAC and DPS” after every restart caused by a voltage failure, for

example.

If the DPC31 receives a Set_Slave_Address message, and if the SAP55 is enabled, the MAC first checks

whether the indication buffer has the corresponding size. If not, the MAC responds with ‘No Resource’.

Otherwise, it sends a short acknowledgement and after the send process transfers this buffer to the DPS

module. The MAC has already accepted the new station address, however.

76543210Byte Name

0-5: Buffer Header

6: New_Slave_Address

7: Ident_Number_High

8: Ident_Number_Low

9: No_Add_Change

10-249: Rem_Slave-Data

Figure 5.2-2:

Assignment in the Data Field of the SSA Indication Buffer

In the following states, the DPS module ignores the SSA indication:

• DP_SM mode ‘Wait_Cfg’, ‘Data_Exchange’

• Net data length less than 4 bytes

• Parameter ‘Real_No_Add_Change’ is ‘True’ (FFh)

• New station address is larger than 125

• Ident No. is wrong

1 2 ... 22 23 24 25 26 27 28 29 30 31 32 ... 93 94

Commenti su questo manuale

Nessun commento

Siemens SPC3 Specifiche Pagina 27

Commenti su questo manuale

Prodotti e manuali riguardandi Networking Siemens SPC3