3-14
MS-890 Industrial Automation Scanner User Manual
Auxiliary Port Protocol
Daisy Chain (Aux Port Mode)
Note:
See also
Daisy Chain Autoconfigure
on page 3-19.
Usage:
Used in applications where:
A symbol might be scanned in both ladder and picket fence directions.
A symbol may be present on multiple sides of a package.
Symbols are presented at different depths.
Definition:
In a daisy chain application, scanners are connected in series or “daisy chain”
and decoded data is relayed from one scanner to another on up to the host.
A master scanner has its host port linked to the host computer and its auxiliary
port linked to the host port of the first secondary scanner in the chain. Thereafter,
each secondary’s auxiliary port is linked to the host port of the secondary that is
further from the host in the daisy chain.
Each scanner in the daisy chain can be assigned an ID that accompanies any
data that it sends.
Serial Cmd:
<
K101,
aux port mode
,
baud rate,parity,stop bits,data bits,daisy chain ID status,
daisy chain ID
>
4 = Daisy Chain
Function:
Before the master scanner times out, it checks its auxiliary port for data. It
should be set to wait at least
20 ms
for each secondary in the daisy chain.
(See
Read Cycle Timeout
on page 4-16.) If no data is received within the
read cycle timeout, the master sends a No Read message to the host. Otherwise
the complete data is sent.
If for example the master scanner is set to timeout in 120 ms, the first secondary
scanner downstream might be set to 100 ms, the next to 80 ms, and so forth,
thus assuring that at least 20 ms elapses between transmissions.
a
Daisy-chained scanners can send a series of symbols by enabling
Multisymbol
and a common multisymbol separator. If the master scanner 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 master and two secondary scanners have
Number of Symbols
set to 3 and
Multisymbol Separator
defined as %. If the master and the first
secondary scanner do not find symbols, but the next secondary scanner
registers a good read, the transmitted results would be:
symbol data % No Read % No Read
a. The above example is based on the best case. Other factors such as baud rate, dynamic
focus timing, number of characters in a given symbol, and the number of secondaries in the
daisy chain can affect timing and may need to be included in your calculations for complete
accuracy.
Summary of Contents for MS-890
Page 1: ...MS 890 Industrial Automation Scanner User Manual P N 84 000890 Rev B...
Page 12: ...xii MS 890 Industrial Automation Scanner User Manual Statement of RoHS Compliance...
Page 26: ...1 14 MS 890 Industrial Automation Scanner User Manual Save Configuration in ESP...
Page 44: ...2 18 MS 890 Industrial Automation Scanner User Manual Send Receive Options...
Page 94: ...4 24 MS 890 Industrial Automation Scanner User Manual Tracking Adjustment...
Page 122: ...5 28 MS 890 Industrial Automation Scanner User Manual Autodiscriminate...
Page 154: ...6 32 MS 890 Industrial Automation Scanner User Manual Quality Output...
Page 168: ...7 14 MS 890 Industrial Automation Scanner User Manual Mismatch Replace...
Page 202: ...9 22 MS 890 Industrial Automation Scanner User Manual Calibration by Embedded Menu...
Page 212: ...10 10 MS 890 Industrial Automation Scanner User Manual Raster Laser by Embedded Menu...
Page 240: ...12 22 MS 890 Industrial Automation Scanner User Manual Scanner Status Requests...
Page 264: ...14 10 MS 890 Industrial Automation Scanner User Manual Mounting Plate...
Page 308: ...A 44 MS 890 Industrial Automation Scanner User Manual Glossary of Terms...