System Startup Time - Omron CJ1W-DRM21 Operation Manual

8 Communications Timing
8-1-4

System Startup Time

Master Function
This section describes the system startup time (estimated) for a network operating with the scan list
enabled. The system startup time is the delay from when the controller is reset or restarted including
turning ON the DeviceNet Unit (master) until remote I/O communications begin. Here, we assume that
the scan list is enabled and that remote I/O communications are set to start automatically at startup.
The following table shows the system startup times for 2 cases. In the first case, the DeviceNet Unit
starts up just after all of the Slaves' power supplies are turned ON. In the second case, the DeviceNet
Unit is restarted while communications are in progress.
Case
The Master is
started just after
Slave startup.
Just the Master is
restarted.
Just the Slaves are
restarted.
Program Example
As shown in the preceding table, it takes time for DeviceNet communications to start up. This pro-
gramming uses flags in the Master status area to prevents the Slaves' I/O processing from being
performed until remote I/O communications start up.
This programming is for a DeviceNet Unit with a unit number of 00.
I/O Data Communications Status
aaaa_Mstr1IOCommSta
Unit Error
aaaa_UnitErr
Slave I/O processing
STEP1:
Processing other than slave I/O
8-8
Slave's indicator status
The NS indicator is OFF or flashing green.
The NS indicator is flashing red while the
Master is OFF.
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STEP1
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
System star-
tup time
(estimated)
13 seconds
15 seconds
9 seconds