Rockwell Automation 1771-IS 5V DC INPUT MOD - Manual (Page 39)

Programming and Operation
Chapter 3
3-20
Other Programming Considerations, PLC-2 Family and PLC-3
When programming block transfer instructions the following should also
be considered.
Automatic/Program Reset, switch #7
When in momentary (latched) contact mode, latched data should be reset
after its image is transferred to the data table. It can be reset by program
logic (program reset mode) or automatically by the module (automatic
reset mode).
In program reset mode, module memory can be reset by user program
after a successful transfer has occurred by setting bit 6 or 16 in the
module’s output image table byte. (Bit 6 is set when the module is in the
lower slot, bit 16 when in the upper slot.) If bit 6 or 16 is set by mistake
during a request for block transfer, the module will respond that it is not
ready to transfer.
Important: Bit 6 or 16 should be programmed only when mode selection
switch #4 and #7 are both in the ON position. Refer to paragraph titled “
Switch Selection of Operating Modes” (Chapter 2).
Reset rungs are illustrated for the PLC-2 family and PLC-3 programmable
controllers in Figure 3.10. The reset condition can be conditioned upon
the completion of a successful block transfer. The output energize
instruction sets the reset bit of the module.
In program reset mode, if any bit in addition to bit 6 or 16 is on, the
module will not reset.