User manual

Chapter 3 Block Transfer Format
22 ADVANCED MICRO CONTROLS INC.
Programming Example
The following example shows a BTR and BTW that accesses the 1761H module. It assumes
1-Slot addressing and the module is in I/O rack 2, I/O Group 5 of the system.
Rung 1: BTR Instruction to the
AMCI module. Data
transferred every scan with
continuous transfer enabled.
Rung 2: Copy File Instruction buffers
the data from the module.
This insures that the program
will use the same data
throughout each scan.
Rung 3: The BT write is enabled
whenever CR1 is latched on.
A BT file controls the
transfer. Note that the
continuous parameter is set
to NO.
Rung 4: CR1 is latched on when a
BTW request is made.
Rung 5: CR1 is unlatched when the
BTW request is removed
and the BTW Done bit is set.
Figure 3.3 PLC-5 Programming Example
BLOCK XFER READ
RACK 2
GROUP 5
MODULE 0
CONTROL N7:20
DATA N7:25
LENGTH 4
CONTINUOUS
Y
(L)
(U)
BTW Request CR1
CR1
BTW Request
BTW
DN
(
EN
)
(ER)
COP
COPY FILE
SOURCE #N7:25
DEST #N7:30
LENGTH 4
(DN)
CR1
BLOCK XFER WRITE
RACK 2
GROUP 5
MODULE 0
CONTROL BT9:0
DATA N14:5
LENGTH 4
CONTINUOUS
N
(
EN
)
(ER)
(DN)