Rockwell Automation GMLC Reference Manual User Manual
Page 740
Publication GMLC-5.2 - November 1999
Using Block Transfers
703
Program Listing Report
PLC-5/30
Rung 2:0
EXAMPLE OF SENDING DATA TO THE MOTION CONTROLLER
| BLOCK
BLOCK
|
| TRANSFER
S CLASS
TRANSFER
|
| SEND DATA
BTW
BTR
PROGRAM
WRITE
|
| CONDITION
ENABLE
ENABLE RUNNING
CONTROL
|
|
I:002
N10:0
N10:5
I:011
+BTW-----------------+
|
+----] [------]/[-------]/[-------] [------+BLOCK TRNSFR WRITE
+-(EN)-+
|
00
15
15
10
|Rack
01|
|
|
|Group
0+-(DN) |
|
|Module
0|
|
|
|Control Block
N10:0+-(ER) |
|
|Data file
N13:0|
|
|
|Length
0|
|
|
|Continuous
N|
|
|
+--------------------+
|
Other interlocks in the BTW rung can be required for your application. At
a minimum, you should have all of the following:
•
A condition that causes the BTW (don’t send a BTW on every PLC
scan).
•
The enable bits (Bit 15 of the BT control block) of all other block
transfers in the ladder.
The block transfer length should always be set to zero, as shown in the
ladder above. This causes all 64 words of the data file to be sent. In
addition, continuous block transfers should not be used.
Using the enable bits from each block transfer to interlock all other block
transfers ensures that the block transfers always occur in the order in
which they appear in the PLC ladder. This is the same technique used to
interlock other RIO devices.