Before the primary reader times out, it
checks its auxiliary port for data. It should be set to wait at
least 30 ms for each secondary reader in the daisy chain. If no
data is received within the read cycle timeout, the primary reader
sends a No Read message to the host. Otherwise the complete data is
sent.
If, for example, the primary reader is set
to timeout in 120 ms, the first secondary reader reader downstream
might be set to 90 ms, the next to 30 ms, and so forth, thus
assuring that at least 30 ms elapses between transmissions.
Daisy-chained readers can send a series of
symbols by enabling Multisymbol and a common multisymbol separator. If the
primary reader does not receive the expected number of symbols, No
Read messages are appended to the data string to make up the
difference between the number of symbols enabled in Multisymbol and the number of
symbols read.
For example, a primary and two secondary
readers have Number of
Symbols set to 3 and Multisymbol Separator defined as %. If the primary and
the first secondary reader do not find symbols, but the next
secondary reader registers a Good Read, the transmitted results
would be:
symbol data % No Read % No Read
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