Rockwell Automation 2706-LV2P_LV2R_LV4P_LV4R DL40 PLUS USER MANUAL User Manual
Page 89
Parallel Port Communications
7–9
Publication 2706-6.1
The strobe line states specify the type of data on the data lines.
MS3
MS2
MS1
MS0
Data Type
0
0
0
0
null
0
0
0
1
D0–D15 contain the message number
0
0
1
0
D0–D15
contain the slave address
0
0
1
1
D0–D9 BCD sign bits for
(Ctrl V) variables 1–10
1
0
0
0
D0–D15 contain variable 1
1
0
0
1
D0–D15 contain variable 2
1
0
1
0
D0–D15 contain variable 3
1
0
1
1
D0–D15 contain variable 4
1
1
0
0
D0–D15 contain variable 5
1
1
0
1
D0–D15 contain variable 6
1
1
1
0
D0–D15 contain variable 7
1
1
1
1
D0–D15 contain variable 8
0
1
1
0
D0–D15 contain variable 9
0
1
1
1
D0–D15 contain variable 10
The number you assign to a variable by setting strobe lines does not
necessarily correspond to the position of the variable in a message.
The DL40 Plus expects to see all
[CTRL][V]
variables numbered
before
[CTRL][W
]
variables.
Triggering Rules Example
If a message has variables positioned as follows:
[CTRL][V]
[CTRL][W]
[CTRL][V]
[CTRL][W]
[CTRL][V]
First
Position
Second
Position
Third
Position
Fourth
Position
Fifth
Position
they must be numbered:
[CTRL][V
]
first position = Variable 1
[CTRL][V]
third position = Variable 2
[CTRL][V]
fifth position = Variable 3
[CTRL][W]
Second and fourth position = Variable 4
Note:
[CTRL][V]
variables always use a (16 bit) word;
[CTRL][W]
variables do not use a full (16 bit) word.
If the variables are not numbered as shown, they would be displayed
in wrong positions and possibly corrupted.
•
If
[CTRL][W]
variables are ASCII (8 bit) variables,
[CTRL][W]
second position
would be sent in the high byte of Variable 4;
fourth position would be sent in the low byte of Variable 4.