Automationdirect.com DirectLOGIC DL205 Series User Manual page 402

Master Line Set (MLS)
The Master Line Set instruction allows the program to control
230
sections of ladder logic by forming a new power rail controlled by the
240
main left power rail. The main left rail is always master line 0. When
a MLS K1 instruction is used, a new power rail is created at level 1.
250-1
Master Line Sets and Master Line Resets can be used to nest power
260
rails up to seven levels deep. Note that unlike stages in RLL
control relays is still scanned and updated even though it will not function if the MLS is off.
Operand Data Type
Constant K
Master Line Reset (MLR)
The Master Line Reset instruction marks the end of control for the
230
corresponding MLS instruction. The MLR reference is one less than
240
the corresponding MLS.
250-1
260
Operand Data Type
Constant K
Understanding Master Control Relays
The Master Line Set (MLS) and Master Line Reset (MLR) instructions allow you to quickly
enable (or disable) sections of the RLL program. This provides program control flexibility.
The following example shows how the MLS and MLR instructions operate by creating a sub
power rail for control logic.
DS Used DirectSOFT
HPP Used
X0
X1
X2
X3
X10
Chapter 5: Standard RLL Instructions - Program Control
DL230 Range DL240 Range
aaa
1-7
DL230 Range DL240 Range
aaa
0-6
PLUS
, the logic within the master
DL250-1 Range
aaa aaa
1-7 1-7
DL250-1 Range
aaa aaa
0-6 0-6
K1
When contact X0 is ON, logic under the first MLS
MLS
will be executed.
Y7
OUT
K2
When contact X0 and X2 are ON, logic under the
MLS
second MLS will be executed.
Y10
OUT
K1
MLR
The MLR instructions note the end of the Master
Control area.
K0
MLR
Y11
OUT
DL205 User Manual, 4th Edition, Rev. B
1
K aaa
MLS
2
3
4
DL260 Range
aaa
5
1-7
6
K aaa
MLR
7
8
DL260 Range
9
aaa
0-6
10
11
12
13
14
A
B
C
D
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