User guide
Appendix
A
A1
Block Transfer (Multiple GET) for PLC2/20
This read-only program (Figure A.1) transfers a block of input data from
the analog input module to a momentary storage (buffer) in the
processor’s data table. If valid, input data is moved elsewhere in the data
table for use by your ladder program. If invalid, it is written over by the
next block transfer. This program performs the same function as the
2-rung program described in chapter 4.
Important: If you place your input module in a local chassis, we
recommend that you add the same rung as described in the PLC-2 family
example (Figure 4.2, Rung 3). This rung guards against the possibility of
the processor repeatedly asking for a block transfer when the module
momentarily inhibits block transfers while updating its inputs.
The example program is based on the following assumptions:
module in rack 1, module group 2, slot 0
8-word block transfer
block transfer (control) address 030
read block transfer (buffer) file 050-057
storage file 150-157
Example Program
Assumptions