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3--12
Installation and Specifications
The
Direct
Logic D2--250/D3--350/D4--450 CPUs and the Allen-Bradley SLC 5/03
and 5/04 support instructions which provide individual status bits access. This is
called
Bit-of-Word
capability. For example, in the previous example, the ladder
logic for the D2--250/D3--350/D4--450 monitors the first bit of the status word directly.
Once again, our example assumes that we configured the OP-panel with a starting
base address of V2000.
There are LEDs located on each of the user defined pushbuttons, indicating
pushbutton status (ON or OFF). You may choose the pushbutton type (alternate or
momentary) while configuring your OP-panel. In the case of an alternating
configured pushbutton, the LED will change state each time the pushbutton is
pressed. With momentary configured pushbuttons the LED is ON only as long as the
pushbutton is being pressed.
The lamp examples shown here are using
Direct
LOGIC PLC address references.
The equivalent instructions for
other
PLC products supported are shown in
Chaper 5.
C1
OP-Control Register
OUT
C20
(DL250,DL350,DL 450 Only)
OUT
V2015.0
PLC Program User Memory
In this example, C1 represents the pushbutton
No.2 (F2) via the mapping process. When
alter-
nating
pushbutton No.2 is pressed internal Con-
trol Relay C20 is true and via mapping process
Control register Bit 0 (L1 Lamp) is energized.
* Control Register (M+13) = V40601: C20 -- C37
M+13
C20 -- C37
Control register
M+13
ON
ON
V2014.1
V40601=
Bit 0: (L1)
LAMP1
Direct bit register access
All lamps may be controlled using the concept shown above. You may use the Lamp
Flash option by controlling the appropriate Flash bit via the ladder logic program.
The example figure below demonstrates how to use the Control register Flash bits
(LF1, LF2, and LF3).
LF3
LF1
Control Register M+13
LSB
LF2
BD
L1
L2
L3
C34
C35
C36
C37
C30
C31
C32
C33
C24
C25
C26
C27
C20
C21
C22
C23
MSB
Pushbuttons Using
Direct Access to
Status Register
Bits
Pushbutton LEDs
Lamp Example