PROFIBUS DP-Master

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6.3.4 PROFIBUS_DL_CMD_DATA_ACK_REQ/CNF - Send SDA Service
This packet provides the SDA (Send Data with Acknowledge) service for acknowledged
connectionless data transfer with immediate response. It allows transparently sending an SDA frame
with variable data length to the PROFIBUS network. At the remote station, the user data (which is
contained in the Service Data Unit represented by the variable abSDU[]) is delivered to the user.
The length of the Service Data Unit is limited to at most 246 bytes
The local confirmation message of this command informs about the receipt or non-receipt of the user
data in the remote station. Within the confirmation packet, a value of ulSta equal to the following
indicates successful receipt of the SDA message:
• TLR_S_OK (0x00000000)
• TLR_E_PROFIBUS_DL_ACK_NR (0xC0060083L)
• TLR_E_PROFIBUS_DL_ACK_DH (0xC0060086L)
• TLR_E_PROFIBUS_DL_ACK_DL (0xC0060087L)
All other values indicate the failure of the SDA service.
Packet Structure Reference
typedef struct PROFIBUS_DL_DATA_ACK_REQ_Ttag {
TLR_UINT8 bSrvCls; /* Service Class */
TLR_UINT8 bDstAddr; /* Destination address */
TLR_UINT8 bDstSAPIdx; /* Destination Service Access Point */
TLR_UINT8 bSrcSAPIdx; /* Source Service Access Point */
TLR_UINT8 abPad[4]; /* Padding needed to bring SDU to a DWORD boundary and to
right position */
TLR_UINT8 abSDU[PROFIBUS_DL_MAX_DLPDU_SIZE]; /* Service Data Unit */
} PROFIBUS_DL_DATA_ACK_REQ_T;
#define PROFIBUS_DL_DATA_ACK_REQ_SIZE (sizeof(PROFIBUS_DL_DATA_ACK_REQ_T)-
PROFIBUS_DL_MAX_DLPDU_SIZE)
/* Request-Packet for acknowledged connectionless data transfer */
typedef struct PROFIBUS_DL_PACKET_DATA_ACK_REQ_Ttag {
TLR_PACKET_HEADER_T tHead;
PROFIBUS_DL_DATA_ACK_REQ_T tData; /* Packet Data Unit */
} PROFIBUS_DL_PACKET_DATA_ACK_REQ_T;
PROFIBUS DP-Master |
DOC061001API12EN | Revision 12 | English | 2010-12 | Released | Public © Hilscher, 2006-2010