Rockwell Automation D64046.5.1 U MNL WIN DDMC User Manual

Page 51

Configuring SDS Instructions

Chapter 4

4-15

The Ins Cmt (Instruction Comment) window on the I/O Definition screen
displays the instruction comment associated with the instruction in the ladder
program. The Adr Cmt (Address Comment) window displays the address
comment for the cursored address in the I/O Defines field.

The maximum number of possible inputs and outputs in the I/O Defines field
correlates with the number of I/O you entered in the Number of I/O field when
programming the SDS instruction.

Important: Consider carefully the order in which you assign I/O points in
the I/O Defines field. The order of I/O assignments can make a significant
difference in the performance of the DDMC32 system.

The order in which an SDS instruction checks I/O information is based on the
equations assigned in a given step (the “current” step). The order of evaluation
is as follows:

single bit transitions –– This includes all inputs that have an equation

assigned to them as ON–> OFF or OFF–> ON

combinatorial equations –– This includes any operations that contain

multiple inputs with either an AND or NOT operand

timers –– This includes any transitions that are generated by a timer (no

inputs are used for this transition)

You can perform the following tasks from the I/O Definition screen:

If you want to:

Press this key:

Enter an operator interface station address.

[F1] - Station Address

Enter a new timebase for the step timer.

[F2] - Timebas

Enter the port number for the message. (PLC-5/250
only)

[F3] - Port

Display the Documentation screen for the SDS
instruction.

[F5] - Documnt

Modify an I/O address at the cursored location.

[F7] - Modify IO Addr

Insert an I/O address at the cursored location.

[F8] – Insert IO Addr

Delete an I/O address at the cursored location.

[F9] – Delete IO Addr

Remove an I/O address at the cursored location.

[F10] – Remove IO Addr

These function keys do not appear on the screen if you have accepted edits once (for example, if you are

modifying the instruction).