10.2.7.2
Parameter Block for the Drum Sequencer Function
The parameter block (control block) for the Drum Sequencer function contains
information needed to operate the Drum Sequencer.
address
Active Step
a 1
Preset Step
a 2
Step Control
a 3
Timer Control
Active Step
The active step value specifies the element in the Pattern array to copy to
the Out output memory location. This is used as the array index into the Pattern, Dwell
Time, Fault Timeout, and First Follower arrays.
Preset Step
A word input that is copied to the Active Step output when the Reset is
On.
Step Control
A word that is used to detect Off to On transitions on both the Step input
and the Enable input. The Step Control word is reserved for use by the function block,
and must not be written to.
Timer Control
Two words of data that hold values needed to run the timer. These
values are reserved for use by the function block and must not be written to.
10.2.7.3
Notes on Using the Drum Sequencer Function
1.
The Dwell Timeout Output bit is cleared the first time the drum is in a new step. This
is true:
•
Whether the drum is introduced to a new step by changing the Active Step or by
using the Step Input.
•
Regardless of the Dwell Time Array value associated with the step (even if it is
0).
•
During the first sweep the Active Step is initialized.
2.
The Active and Preset Step of the Drum Sequencer’s control block must be
initialized for the Drum Sequencer to work or to pass power flow. Even if the Active
Step is in the correct range (between 1 and length of the Pattern array) and the Preset
Step is not used, the drum will not function if the Preset Step is not in the proper
range.
146
GFK-1503E
VersaMax PLC User Manual
For public disclosure
Summary of Contents for VersaMax PLC
Page 16: ...Notes 16 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 38: ...Notes 38 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 50: ...Notes 50 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 92: ...Notes 92 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 112: ...Notes 112 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 224: ...Notes 224 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 292: ...Notes 292 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 316: ...Notes 316 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 317: ......