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Rockwell Automation 1785-Lx0C15 ControlNet PLC-5 Programmable Controllers User Manual User Manual

Page 82

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1785-UM022C-EN-P - February 2008

4-2

The fields of the MG data type that you can directly address are:

For more detailed information about writing ladder programs and
using message instructions, see your programming software
documentation.

Multihop Messaging Via the MSG Instruction

You can use the MSG instruction to communicate from a processor
on one ControlNet link to a processor on another ControlNet link via
ControlBus using 1756-CNB ControlNet bridge modules.

You can also configure a ControlNet ladder MSG instruction to:

a Data Highway Plus device by bridging across the 1756-CNB(R)
and 1756-DHRIO modules

an Ethernet device by bridging across the 1756-CNB(R) and
1756-ENET modules

Refer to your programming software documentation for information
about configuring multihop messages.

enter the size in
elements

Type a number of elements from 1 to 1000.

enter the destination
network address

Type a number from 1 to 99.

enter a destination
data table address

Type the destination data table address.

If you want to:

Do this:

Field

Definition

Location

.EW

Enabled-waiting flag bit

word 0, bit 02

.CO

Continuous control bit

word 0, bit 03

.ER

Errored flag bit

word 0, bit 04

.DN

Done flag bit

word 0, bit 05

.ST

Started flag bit

word 0, bit 06

.EN

Enabled flag bit

word 0, bit 07

.TO

Abort (Time out) control bit

word 0, bit 08

.NR

No-response flag bit—not used

word 0, bit 09

.NC

No-cache bit

word 0, bit 10

.ERR

Error-code word

word 1

.RLEN

Requested length word

word 2

.DLEN

Done length word

word 3

.DATA[0] through.DATA[51]

Remaining words

words 4 through 55

1756-CNB

ControlBus

ControlNet Link 1

ControlNet Link 2