Omron CJ1W-PRT21 Operation Manual page 49

Name
Fail-Safe Support
Watchdog Base
Output data on PROFI-
BUS fail
Output data format
Output to slave PLC area The user can select the area to which the unit will write PROFIBUS output data received from its
Output area start
address
Action on slave PLC
PROGRAM mode
Action on slave PLC I/O
bus fail
CJ-series PROFIBUS Slave Unit Operation Manual for NJ-series CPU Unit (W510)
ON: After the master sends a global control command 'CLEAR', the slave can accept data tele-
grams containing no data, while still remaining in data exchange mode
OFF: After the master sends a global control command 'CLEAR', the slave requires data telegram
containing 0000 as data in order to remain in data exchange mode.
The slave uses the watchdog control to detect failures of the master or the transmission line. If no
data communication with the master occurs within the watchdog control interval, the slave automat-
ically switches its outputs to the fail-safe status. The watchdog control time can be specified in
intervals of 1 ms or 10 ms.
The user can select how the slave will behave on the host CPU's I/O bus in the event the PROFI-
BUS data exchange communications fails
• Clear data to Host CPU
• Hold data to Host CPU
The user can select how the data bytes of a PROFIBUS data exchange telegram are mapped to
the host CPU data words.
• Motorola
• Intel
See 3-3 I/O Data Format for details
master.
Sets the start address in the host CPU to which the PROFIBUS output data, received from the
master, will be written.
Defines how the slave will behave on PROFIBUS in the event the host CPU is in PROGRAM mode
(as opposed to RUN mode).
Defines how the slave will behave on PROFIBUS in the event the host CPU has a fatal error (CPU
ERC indicator ON) or communication with the host CPU is lost e.g. I/O refresh timeout.
1 Features and System Configuration
Description
1
1-11