User guide

9: Client Applications — Commands and Responses
DC 900-1338I 175
9.2.7.1 Configuring the ICP Link
After the client has issued an attach command to the ICP, but before it issues a bind com-
mand, it can send ICP link configuration values to the ICP. If no configuration message
is received by the ICP, the default link configuration is used. When the ICP receives a
configuration message, it validates it and updates the current link configuration. First
the client allocates a buffer for the
CONF_TYPE structure and fills in the structure. Next
the client establishes a
DLI_OPT_ARGS structure requesting the write, then sends the
structure along with a buffer containing the configuration to the ICP.
To set the link configuration options, a buffer containing the structure shown in
Figure 9–12 is sent to the ICP. The fields of the data structure are set to appropriate val-
ues by the client application.
/* Structure of configuration request message */
struct conf_type
{
bit8 protocol
1
; /* With Ack: 0x00=BSC, 0x01=Async, 0x02=SDLC */
/* W/out Ack: 0x80=BSC, 0x81=Async, 0x82=SDLC */
bit8 clock; /* 0 = external, 1 = internal clock */
bit8 baud_rate; /* index into baudsc or baudas */
bit8 encoding; /* 0 = NRZ, 1 = NRZI (SDLC only) */
bit8 electrical; /* electrical interface icp24xx */
bit8 parity; /* 0 = none, 1 = odd, 2 = even */
bit8 char_len; /* 7 = 7 bits, 8 = 8 bits */
/* (asynch only) */
bit8 stop_bits; /* 1 = 1 stop bit, 2 = 2 stop bits */
/* (asynch only) */
bit8 crc; /* 0 = no CRC, 1 = CRC */
/* (SDLC always uses CRC) */
bit8 syncs; /* # of leading sync chars (1-8) */
/* (BSC only) */
bit8 start_char; /* block start character */
/* (not used for SDLC) */
bit8 stop_char; /* block end char (asynch only) */
};
typedef struct conf_type CONF_TYPE;
1
Specifying a protocol with Ack enables DLI_PROT_RESP_LOCAL_ACK transmission acknowledgment messages
for the link. Specifying a protocol without Ack disables DLI_PROT_RESP_LOCAL_ACK messages for the link
Figure 9–12: Link Configuration “C” Structure