Rockwell Automation 1779-KP3R DATA HIGHWAY II - Manual (Page 48)

Programming
Chapter 3
3Ć13
When another node reads the immediate–access block, it does not have to
wait as long to receive a reply. Usually, the node that receives a command
must wait to receive the token before it can reply to a command. With the
immediate–access block, the node that receives the command can transmit
a reply without having to wait to receive the token first. Thus the node
that sent the command, receives a reply sooner.
To transfer data using the immediate blocks, use the TMOVE command to
update the data in the local node’s immediate blocks and/or to read data
from some remote node’s immediate blocks.
Based on the nature of data, the user program must update the local node’s
immediate blocks at the selected time interval. In the following example,
we show a user program that updates the immediate block in the local
KP3 at 5–second intervals (figure 3.3), then one that reads it (figure 3.4).
Figure 3.3
User Program to Initiate and Update Immediate Blocks at Five-Second Intervals
MSG
MESSAGE TYPE 1
CTL=FB020:0000= 0
CH:E2.9.1
TMOVE FROM $A1:0,5
TO &1
( EN )
STAT
( DN )
STAT
( ER )
STAT
12
15
T0005
15
WB020:0000 WB020:0000
15
13
TON
( TE )
( TD)
T0005
17
15
T0005
T0005 TIMER ON
0.1 SECOND
TP = 50
TA = 0
12
WB020:0000
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Figure 3.4
User Program to Read Immediate Blocks
MSG
CTL=FB001:0000= 0
CH:E2.9.1
TMOVE FROM :17&1 TO
$N0:0,5
( EN )
( DN )
STAT
( ER )
STAT
12
15
STAT
MESSAGE TYPE 1
I0:10
02
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