Installation guide

4: Commands and Responses

DC 900-1564A 41

4.3 Data Category

The commands and responses in the Data category are used to transfer data on the

speciﬁed SLC network connection. Only an application session with Master access

mode can use this category.

4.3.1 Safe Store Acknowledgment

DLI_PROT_SAFE_STORE_ACK can be used only when SLC protocol service is configured. It

is not supported when SLC envelope service is conﬁgured. The header formats are

detailed in Section 5.14 on page 78.

After reading a

DLI_PROT_SEND_NORM_DATA response or a DLI_PROT_SEND_PRIOR_DATA

response, the application extracts the iProtModifier ﬁeld value (the ICP message iden-

tiﬁer), performs any required message protection operations, then using the same

iProtModifier field value writes the DLI_PROT_SAFE_STORE_ACK command to acknowl-

edge that the message has been stored safely. The ICP examines the

iProtModifier ﬁeld,

and if necessary transmits a link control block with the corresponding acknowledge

message label (AML) on the speciﬁed SLC network connection.

When the application writes a

DLI_PROT_SEND_NORM_DATA command or a

DLI_PROT_SEND_PRIOR_DATA command, the ICP uses the iProtModifier field value to

compute a corresponding message block identiﬁer for each information block trans-

mitted. The application reads a

DLI_PROT_SAFE_STORE_ACK response when the ICP

receives a link control block containing a corresponding acknowledge message label

from the SLC network. If the

iICPStatus field value is DLI_ICP_CMD_STATUS_OK, receipt

of a

DLI_PROT_SAFE_STORE_ACK response constitutes acknowledgment that the speciﬁed

message has been stored safely at a remote site. If the

iICPStatus field value contains a

negative error code value, receipt of a

DLI_PROT_SAFE_STORE_ACK response constitutes a

failure in message transmission or a rejection of the speciﬁed message by the remote

site.