Rockwell Automation 22-COMM-D DeviceNet Adapter User Manual

Page 60

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6-4

Using Explicit Messaging

Explicit Messages for a PLC or SLC Controller

Transaction blocks in PLC and SLC scanners accommodate both
downloading Explicit Message Requests and uploading Explicit
Message Responses. The scanner module can accommodate one request
or response for each transaction block. Each transaction block must be
formatted as shown in

Figure 6.2

or

Figure 6.3

.

Figure 6.2 PLC Explicit Message Format

Figure 6.3 SLC Explicit Message Format

Refer to

Page 6-5

and

Page 6-6

for a description of the data that is

required in each word.

Bit 15

0

15

0

Word 0

TXID

Command

TXID

Status

Port

Size

Port

Size

Service

Address

Service

Address

Class

Service Response Data

Instance

Attribute

Word 6 - 31

Service Data

Word 32

TXID

Command

TXID

Status

Port

Size

Port

Size

Service

Address

Service

Address

Class

Service Response Data

Instance

Attribute

Word 38 - 63 Service Data

Bit 15

0

15

0

Word 0

TXID

Command

TXID

Status

Port

Size

Port

Size

Service

Address

Service

Address

Class

Service Response Data

Instance

Attribute

Word 6 - 31

Service Data

Request

Response

Request

Response

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