Rockwell Automation 1771-IS 5V DC INPUT MOD - Manual (Page 23)

Programming and Operation
Chapter 3
3-4
Momentary Contact Mode
When 4-digit BCD thumbwheel switches are wired according to the block
diagram in Figure 3.3a, the switch settings will be stored automatically in
the data table after a block transfer as shown in Figure 3.3b. The first
word is reserved for diagnostic data. Each remaining word stores the 4
digits of the thumbwheel setting. The digits MSD, UMD, LMD and LSD
have been loaded, respectively, from left to right, in the opposite byte
order from which they normally read (left to right). For example, observe
how the 4-digit switch setting 9753 of thumbwheel switch #2 is loaded
into the data table.