30
Don’t worry if you don’t understand the meanings of all of the fields listed
above at this point: their significance will be explained in detail later during the
console configuration portion of this manual. In a similar fashion to parameter
#1, we can enter the remainder of the parameters (#2 - #12) to correspond to
the secondary network architecture provided in Table 3.
While the mapping function provided by configured parameters may be
obvious, there is another less-apparent service that they also provide. This
service is termed
data mirroring
, whereby current copies of secondary
network object values are maintained locally within the gateway itself. This
greatly reduces the primary network’s request-to-response latency time, as
read and write requests can be entirely serviced locally, thereby eliminating the
time required to execute a secondary network transaction.
Another advantage afforded by the ability to map secondary network objects to
any available DeviceNet parameter number is the capability of
data
reorganization
. Data reorganization allows the grouping of secondary
network objects into more logical or efficient patterns. Because the DeviceNet
network tool or scanner never “sees” the true secondary network addresses or
object indexes (i.e. register numbers), the secondary network address/object
assignment can be determined by any user-defined criteria (physical unit
position on the floors of a building, for example), while allowing the DeviceNet
parameter assignments to be chosen using a different criteria (grouping
according to device application or function, for example). For instance, if three
ASDs were connected to a DNET-100 gateway, parameters #1, #2 and #3
could be assigned as the frequency commands of ASD #1, ASD #2 and ASD
#3, respectively.
Once the attributes of each parameter have been entered, the final results of
the overall assignment are given in Table 4. The information residing on the
Modbus devices can now be accessed via standard DeviceNet parameter
access methods.
Table 4: Final Parameter Assignment Example
DeviceNet
Parameter
Modbus Address/
Register
Note
1
5 / 10
Frequency command
2
5 / 15
Operating frequency
3
5 / 120
Run/Stop command
4
5 / 125
Run/Stop status
5
7 / 2
Temperature sensor
6
7 / 4
Digital output
7
9 / 8
Voltage monitor #1
8
9 / 9
Voltage monitor #2
9
9 / 10
Voltage monitor #3
10
11 / 8
Voltage monitor #1
11
11 / 9
Voltage monitor #2
12
11 / 10
Voltage monitor #3
Summary of Contents for DNET-100
Page 8: ...7 2 Mechanical Diagrams 2 1 Enclosure Figure 2 Enclosure Dimensions units are inches ...
Page 9: ...8 2 2 Mounting Clip Figure 3 Mounting Clip Dimensions units are inches ...
Page 11: ...10 ASD Link LEDs Reserved LEDs ASD 2 ASD 3 ASD 1 Figure 6 Top View ...
Page 39: ...38 Figure 15 HyperTerminal Configuration Screen 3 ...
Page 68: ...67 16 Notes ...
Page 69: ...68 ...
