Baumer Ident OIS-P PC 3100 series, Руководство по установке

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OIS-P, PC3141/03 Manual Baumer Ident 15
2.1.3 Total communication time
Point-to-point connection
The total time required for communication between
the host system and the Data Tag is calculated by
adding the Data Tag communication time (Table
2.a) to the host communication time (Table 2.b).
This will result in a total communication time based
on the following conditions:
* The host has a response time of 10 ms.
* The OIS-P system is connected to the host
in point-to-point connection.
If the serial interface response time in the host is
significantly longer than the stipulated 10 ms, the
additional time will have to be added three times.
Multidrop connection
In case OIS-P communicators are connected in a
multidrop configuration, the following guidelines will
apply for determining the total time required for
moving data between Data Tag and host:
a/ If each Communicator’s task is performed
from start to finish, without delay due to host
communication with other units, the total time
required for moving data between Data Tag
and host will be the same as for a point-to-
point connected unit.
b/ However, if the system engineer designs the
application software program in a way, that
the process of moving data between Data
Tag and host may be interrupted by host
communication with other Communicators,
an object must remain in front of an antenna
for a longer time than in a point-to-point
situation.
How much longer this required time will be,
depends on how the system engineer has
designed the application specific software in
the host.
Example
Let’s assume initial production requirements are to
be written to a PC 3105/00D Data Tag at the start
of a production line. The Data Tag is present
(moving or stationary) in the communication zone
for 10 seconds. 30 files with an average size of 100
bytes are to be written. The host communication
baudrate can be chosen to satisfy the time
requirements. The OIS-P is connected to the host
in a point-to-point configuration and the response
time for the host is less than 10 ms.
Time required
at different baud rates
Sequence: 9600: 19200:
Host to central unit time
(30 x 0.19/30 x 0.11)
5.7 3.3
Central unit to escort
memory time
30 x 0.16
4.8 4.8
Total: 10.5 8.1
Table 2.c Example on total communication time.
Result:
The baudrate 19200 should be used for sufficient
margins. A faster solution would be to use the
command buffer. All data can be loaded into one
buffer before the Data Tag arrives to the
communication zone.
With a command buffer containing CO (Copy Buffer
to Buffer) and LD (Load) there is no need for a
communication to the host for every file.
The resulting time in the example above would be
less than 5.0 s., i.e. a recommendable margin of a
factor 2.
System performance