Programming techniques chapter 5 – Rockwell Automation 1775-MX_S4A,D17756.3.1 User Manual PLC-3 BACKUP CONC(OR.DU1 User Manual
Page 95
Programming Techniques
Chapter 5
5-14
Important: Upon completing the program compare function, the memory
communication module sets either bit 12 or 13 in status file 4, word 0, to
show the condition of the transferred data. You must reset these bits before
checking the status of the next program compare function.
Table 5.B
Status File 4, Word 0 in the Data Table
Bit:
Meaning:
00
On when the backup processor is in the run mode.
01
On when the backup processor is in the test mode.
02
On when the backup processor is in the program mode.
03
On when the backup processor is faulted.
04
On when the backup processor has its outputs enabled.
05
On when the backup processor is locked.
06
On when the primary processor is locked.
07
On when a communication error has occurred.
10
On when backup to primary data transfer is enabled.
11
On when LIST is controlling operation of the 1775ĆMX modules. Off when the ladder
program is controlling operation of the 1775ĆMX modules.
12
On when the program compare function detects an error.
13
On when the program compare function has successfully executed a complete pass.
14
On when the program compare function is enabled.
Upon completing the program compare function, the 1775ĆMX module sets either bit
12 or 13 to show the condition of the transferred data. In order to check the status for
the next program comparison, you must reset these bits.
15
On when a data table transfer is selected. Off when a file transfer is selected.
16
On when a continuous transfer is selected. Off when a single transfer is selected.
17
On when the 1775ĆMX modules are transferring data from the primary to the backup
processor.
Bit 17 preconditions bits 15 and 16.