Rockwell Automation 2705 REDIPANEL KEYPAD MODULE USER MANUAL - Manual (Page 45)

Chapter 7
Programming
7–7
In Figure 7.4, function key F3 is used to initiate a MOVE instruction. The
MOVE instruction, moves the constant 3 to the Keypad module’s stored
message word 0:022. This in turn triggers stored message number 3
“16
CHARACTER MSG.” .
The second rung in Figure 7.4, Rung 2:4 uses a Greater Than/Equal To
instruction (GEQ) to control the DM bit. In this case, if the message number
being displayed is 3 or more, the DM bit 16 is turned on to allow all 16
characters of the message to be displayed.
The GEQ or LEQ (Less Than/Equal To) instruction can be very useful in this
application. For example, if your application requires (30) 16 character
messages, use the stored message numbers between 90 and 120. Then you
may use the GEQ instruction to turn on the DM bit anytime a stored message
number of greater than or equal to 90 is moved to the Keypad. If you wish to
use the LEQ instruction, you would enter those (30) messages using the first
available stored message numbers of 1 through 30.
To enter or change values in the PLC–5 with the keypad data must be moved
from the Input Image table of the Keypad Module to the PLC–5.
Figure 7.5 below shows one example of the ladder logic required to change a
PLC–5 counter preset value.
Entering or Changing Data with
the Keypad Module