16
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HSLink Introduction
1.4.5
Networking Topology
As described above, the HSLink system is of RS422 with multi -drop
architecture. Base on this architecture, there are a variety of methods to
networking a HSLink circuit, e.g .: serial, multi -drop, star … etc. It is very
difficult to enumerate all the possible network topologies and the detail
specifications. Instead, some real cases are presented here and they
should be helpful to give senses.
Ø
Serial wiring:
All the slave I/O modules are connected one by one with twin-head
100BaseTX cables.
Figure 1.14: HSLink networking topology – Serial
Because the 2 notches of any slave I/O module’s termination board are
actually short circuit, this kind of wiring provides the easiest and most
intuitive way to form a HSLink network. And, the longest wiring length is
200m.
1.4.6
I/O refreshing rate of HSLink system
Once the maximum slave address used in one HSLink system is decide.
The polling cycle time of this HSLink system will be known, also. Here is the
formula:
Polling cycle time = maximum-address-of-slave * 30.1 µ sec.
Maximum address
Polling time
5
150.5 µ sec.
10
301.0 µ sec.
20
602.0 µ sec.
30
903.0 µ sec
40
1.204 m sec
50
1.505 m sec
60
1.806 m sec
63
1.895 m sec
Table 2: Polling cycle time of HSLink
RJ45/10BaseT
Slave I/O Module
HSL Master
PCI-7851/7852
IPC
8R/16DI
16DI/16DO
16DI
Other PCI Cards
