Message Communications Characteristics; System Startup Time; Message Communications Time - Omron E5ZN-DRT Operation Manual

Message Communications Characteristics

7-1-4

System Startup Time

Program Example
7-2

Message Communications Characteristics

7-2-1

Message Communications Time

118
This section describes the system startup time for a Network, assuming that
the scan list is enabled and that remote I/O communications are set to start
automatically at startup. The system startup time is the delay from the time
that the Master Unit is turned ON or restarted until the time remote I/O com-
munications begin.
The system startup time when the Master Unit is set to start up immediately
after power supplies of all the slaves' are turned ON is different from when the
Master Unit is restarted while communications are in progress. The startup
times are shown in the following table.
Condition
The master is started
immediately after slave
startup.
The master only is
restarted.
The slaves only are
restarted.
As shown in the preceding table, it takes time for DeviceNet communications
to start up. This programming uses flags in the Master Status Area to prevent
the slaves' I/O processing from being performed until the Master Unit and
remote I/O communications have started up.
Note Refer to the operation manual of the Master Unit being used for details on the
Master Unit Status Area.
The following program example is for a CS-series PLC and a Master Unit with
a unit number of 00.
2001 2001
15 14
I/O Data
Communications
Flag
Error/Communic
ations Stopped
Flag
The message communications time is the time required from the time a Mas-
ter Unit starts to send a message over the Network to another node until the
Master Unit completes sending the message (SEND/RECV instructions to
send/receive data and CMND/IOWR instructions to execute FINS com-
mands).
Note If the CPU Unit attempts to send another message or receives a message
from another node before the message communications time has finished, the
Slave's indicator status
NS indicator is OFF or flashing green. 6 s
NS indicator is flashing red while the
master is OFF.
-
(004)
JMP #0001
Slave's I/O
processing
(005)
JME #0001
Section 7-2
System startup
time
8 s
10 s