<Toc> <Ind>
<2. Overview of DeviceNet >
2-3
IM 34M6H28-01E
1st Edition : Feb.01,1999-00
2.2
I/O Communications (I/O Slave Message)
This is a communication function which allows the exchange of control information (I/O
data) between the master and a slave in real time.
This module supports the following two types of I/O communications protocols of
DeviceNet.
Polling .......... Sends polling instructions containing output data from the master to a
specified slave; the master then receives a response containing the input
data from the slave
(1 : 1 communication).
Bit Strobe ..... Multicasts (broadcasts) Bit Strobe request instructions from the master to
multiple slave systems and receives a response with input data from each
slave. A communication request that can be transmitted to multiple slaves
at a time (1:N communications) will improve network throughput. However,
this is possible only in the case of slave systems with input data of less than
8 bytes.
In this module, transmission of I/O communications requests is cyclic. This period (trans-
mission time interval) can be specified for all the slaves in a batch in 5 ms intervals.
Cyclic Request
Bit Strobe request instructions
Request/response with data
Response without data
This module (Master)
Input data
Input data
Output data Input/Output data
DeviceNet
F0202.EPS
Slave
Slave
Slave
Slave
Figure 2.2 I/O Communications Concept Diagram
SEE ALSO
For information on I/O communications functions other than Polling and Bit Strobe, see also the
“DeviceNet Specification” published by ODVA.
Содержание FA-M3 Vitesse
Страница 2: ...Blank Page...
Страница 28: ...Blank Page...
Страница 40: ...Blank Page...
Страница 94: ...Blank Page...
Страница 116: ...Blank Page...
Страница 118: ...Blank Page...