Manual

ManualsBrandsRockwell Automation ManualsEquipment1771ACN/B_1771ACNR/B,D17716.5.123 U.MNL CONTROLNET ADAPTER

Appendix

Publication

1771-6.5.123 – May 1996

A Practical Example of

ControlNet Concepts

01234567

I/O Chassis Slot Number

PLC-5/40C

01234567

1771-VHSC

1771 8 Point In

1771 8 Point Out

1771-P4S

Node

Empty

Map

File

Size

I:10 1

O:23 2

1771-A2B Chassis set

for 2-slot addressing

This example uses the physical layout and map entry screen for a

simple system as shown above. W

ith this layout:

• any legal input module in slots 0 and 1 will be read

• any legal output module in slots 0 to 3 will be properly

controlled

• you can communicate with nondiscrete modules anywhere in

the chassis

In this example:

• the input file size is not equal to the output file size

• the input file location (I:10) is not equal to the output file

location (O:23)

• the module node address is not related to the input file (I:10)

or the output file (O:23)

• you can map odd numbered file sizes (I:10 = 1) and file

locations (O:23)

• you can perform nondiscrete file transfers to slots not mapped

into I/O image space (1771-VHSC in slot 4)

• the chassis is mapped as slots 0 to 7 regardless of the

addressing mode used (2, 1, or 1/2)

• all 1771 I/O placement rules for discrete (8, 16 and 32 point)

and nondiscrete modules as defined for addressing modes still

apply (refer to chapter 3).

• any discrete output modules placed in slots 4 through 7 will

behave as if they are being written all zeroes

• any discrete input modules placed in slots 2 through 7 will not

be read by the programmable controller

w of E