User`s guide

2: DDCMP DLI Functions

DC 900-1343D 49

2.6.1 Received Data

The DDCMP software provides the DLI_PROT_RECV_DATA dlRead response code for

data reception. The buffer pointed to by the

pBuf parameter contains 16 empty bytes

followed by the received data. The

dlRead iBufLen parameter equals the size of the data

(in bytes) + 16. The

dlRead function returns a non-zero pOptArgs.iICPStatus ﬁeld if

there is an error associated with the message (see Appendix A).

The

pOptArgs.iProtModifier ﬁeld deﬁnes the type of message received as shown in

Table 2–12 (for incoming data). Section 2.6.1.1 through Section 2.6.1.4 give details.

2.6.1.1 Normal or Maintenance Data [0]

Normal or Maintenance Data is indicated by the DLI_PROT_RECV_DATA dlRead response

code with the

pOptArgs.iProtModifier ﬁeld set to zero. The packet data area contains

the actual line data received in a single DDCMP frame. This message type is generated

by the ICP. See Section 3.7 on page 58 to set the maintenance mode conﬁguration

option.

2.6.1.2 Final Acknowledge of Data Transmitted [7]

The Final Acknowledge of Data Transmitted (either normal or maintenance data) is

indicated by the

DLI_PROT_RECV_DATA dlRead response code with the

Table 2–12: Received Data:

pOptArgs.iProtModifier Field Values

Type of Received Data

Value of Field

pOptArgs.

iProtModifier Reference Section

Normal or Maintenance Data 0 Section 2.6.1.1

Final Acknowledge of Data Transmitted 7 Section 2.6.1.2

Final Acknowledge of Start Link 9 Section 2.6.1.3

Final Acknowledge of Stop Link 11 Section 2.6.1.4