AutomationDirect DL105, Руководство пользователя

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Drum
Instruction
Programming
6--11
Drum Instruction Programming
DL105 PLC User Manual, 3rd Edition
In the figure below, we focus on how the Jog input works on event drums. To the left
of the diagram, note that the off-to-on transitions of the Jog input increments the
step. Start may be either on or off (however, Reset must be off). Two jogs takes the
drum to step three. Next, the Start input turns on, and the drum begins running
normally. During step 6 another Jog input signal occurs. This increments the drum to
step 7, setting the timer to 0. The drum begins running immediately in step 7,
because Start is already on. The drum advances to step 8 normally.
As the drum enters step 14, the Start input turns off. Two more Jog signals moves the
drum to step 16. However, note that a third Jog signal is required to move the drum
through step 16 to “drum complete”. Finally, a Reset input signal arrives which forces
the drum into the preset step and turns off the drum complete bit.
Start
0
1
Reset
0
1
Step #
Drum
Complete (CT0)
0
1
Inputs
1 2 3 3 3 4 5 6,7 8 ... 14 15 16 16 16 1
Drum Status
Jog
drum
Reset
drum
Jog
drum
Drum
Complete
0
1
Outputs (x 16)
Jog
0
1
Jog
drum
Applications often require drums that
automatically start over once they
complete a cycle. This is easily
accomplished, using the drum complete
bit. In the figure to the right, the drum
instruction setup is for CT0, so we logically
OR the drum complete bit (CT0) with the
Reset input. When the last step is done,
the drum turns on CT0 which resets itself
to the preset step, also resetting CT0.
Contact X2 still works as a manual reset.
f f F f f f
f f f f f f
f f f f F f
F F f F F f
f F F f F f
f F F f F F
f F f f F F
f F F f f F
Outputs
Steps
Setup
Info.
X0
X2
Start
Reset
CT0
X1
Start
The outputs of a drum are enabled any time the CPU is in run mode. On
program-to-run mode transitions, the drum goes to the preset step, and the outputs
energize according to the pattern of that step. If your application requires all outputs
to be off at powerup, make the preset step in the drum a “reset step”, with all outputs
off.
Each event-based transition accepts only one contact reference for the event.
However, this does not limit events to just one contact. Just use a control relay
contact such as C0 for the step transition event. Elsewhere in ladder logic, you may
use C0 as an output coil, making it dependent on many other “events” (contacts).
Self-Resetting
Drum
Initializing Drum
Outputs
Using Complex
Event Step
Transitions