Allen-Bradley PLC-5 User Manual page 98

6-26 Communicating with Remote I/O
Publication 1785-UM012D-EN-P - July 2005
Bit Layout Diagrams for the Second Word Allotted to a Remote I/O Rack or an
Extended Local I/O Rack
N15:15
15 14 13 12
Not Used
This Bit:
Inhibit Bits
Reset Bits
ATTENTION
Reset Bits
11 10 09 08 07
Corresponds to:
00 first 1/4 rack
starting I/O group 0
01 second 1/4 rack
starting I/O group 2
02 third 1/4 rack
starting I/O group 4
03 fourth1/4 rack
starting I/O group 6
08 first 1/4 rack
starting I/O group 0
09 second 1/4 rack
starting I/O group 2
10 third 1/4 rack
starting I/O group 4
11 fourth1/4 rack
starting I/O group 6
When you use a ladder program or the software to
inhibit and reset an I/O rack, you must set or clear the
reset and inhibit bits that correspond to each quarter
rack in a given chassis. Failure to set all the appropriate
bits could cause unpredictable operation due to
scanning only part of the I/O chassis.
Inhibit Bits
06 05 04 03 02
Not Used
01 00