
B-63404EN/03 OPERATION 2.CONFIGURING A SAFE SYSTEM
- 67 -
2.1 TROUBLESHOOTING COMMUNICATIONS ERRORS
Using the Series 16i/18i/21i-A/B (DeviceNet function software series 6576/edition 02
or earlier)
With this DeviceNet function, assignment data is not updated when a
communications error occurs. For this reason, DI data is held at the
state that was active when the alarm was detected.
Using the Series 16i/18i/21i-A/B (DeviceNet function software series 6576/edition 03
or later) or Series 15i-A
In this DeviceNet function, whether to hold or clear the DI data when
a communication error has occurred can be selected by setting the DI
HOLD/CLEAR parameter as follows:
DI HOLD/CLEAR
0: The DI data is held in the state where it was when an alarm
condition was detected.
1: The DI data is cleared.
When designing the system, design the system so that the status of the
status information is monitored at all times and the system operates
stably. You can also prepare signals in DI/DO data, by which data is
exchanged, for indicating whether or not communications is being
performed instead of using the status information, and you can also
judge whether or not communications is being performed normally by
monitoring whether or not chose signals are being read. On the slave
system side, start and continue operations after receiving permission
from the master device.