Rockwell Automation 1771-KA2 Communication Adapter Module - Manual (Page 82)

Command Initiation, Execution, and
Monitoring
Chapter 7
7-10
Figure 7.5
Timer-Initiated Command
033 12
Remote Fault
033 02
Local Fault
U
032 12 032 02
Done Start
TON
046
1.0
032 02
/
Done
L
032 12 046 15
Timed Bit Start
PR 010
AC 000
In this example, timed bit 04615 is used to initiate the command at every
preset interval, 10 seconds. This bit is examined to LATCH the START
bit. The DONE, LOCAL FAULT, and REMOTE FAULT bit are
examined in parallel branches to UNLATCH the START bit.
In normal operation, after the command is executed, the DONE bit is set
ON by the communication adapter module. This causes the program to
UNLATCH the START bit. The timer then begins timing again once the
DONE bit is set OFF. (As Figure 7.1 shows, the DONE bit is reset only
after the START bit is reset.)
Note that this programming causes continuous re-try of a command in the
event of faulted operation.
When it cannot execute a command, the Communication adapter module
sets a REMOTE or LOCAL FAULT bit ON. These bits, in the data table
of the station processor, are located in the word immediately following the
START/DONE bit word. They indicate not only that a command was not REMOTE/LOCAL FAULT Bit
Monitoring