User`s guide

4: FMP Link Conﬁguration Options

DC 900-1339H 81

4.11.2 DSR and DCD Signals

Line activity ceases when the signal on the DSR pin is lost. With either the HDX-2 or

FDX-2 setting, the incoming DSR signal is ignored by the FMP software. This setting is

useful when DSR may not be present.

4.12 Feed ID Option (18)

This option lets the application program assign a number to a conﬁguration. For exam-

ple, if an application program services a given number of multiple links or communi-

cations servers, the conﬁguration feed ID is used to determine what market feed that

line is conﬁgured for. In other words, the user application assigns unique feed IDs to

every different market feed. The user application can then identify the market feed by

using the feed ID option. This option has no effect on the FMP software.

To set this option using the DLI conﬁguration ﬁle, use the

feedID parameter; for exam-

ple,

feedID = 0. See Table 5–1 on page 104.

4.13 Message Blocking Option (19)

This option controls the logical blocking and deblocking of data between ICP message

buffers (Section 3.4.1.3 on page 48) and transmission blocks (Section 4.7 on page 72)

during normal link operation. See Section 2.1.6 on page 32 for more information on

message buffers and transmission blocks. This option, in conjunction with the Data

Packing option (Section 4.9 on page 74), determines how received data is formatted in

an FMP buffer. Table 4–3 summarizes the Message Blocking option settings for received

data.

Before determining which setting is best for your application, it is important to know

the difference between a data block and a data record. A data block starts with STX or

SOH and ends with ETB or ETX followed by a BCC (block check character). A block

can contain one or more records. Multiple records within a block are separated by unit

separator (US) or record separator (RS) characters. Data feeds that use US characters to