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Binary command language appendix a, Figure a.1 bcl protocol diagram, A-13 – Rockwell Automation 1775-S5_SR5,D17756.5.5 User Manual PLC-3 FAMILY I/0 User Manual

Page 141

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Binary Command Language

Appendix A

A-13

Figure A.1

BCL Protocol Diagram

1

2

External Device

PLCĆ3

External Device

PLCĆ3

External Device

PLCĆ3

External Device

To Sheet 2

From Sheet 2

ACK
Break

Character

Timeout
Invalid

Response

NAK

Terminate

Communication

Terminate

Communication

Channel

Timeout

Break

Terminate

Communication

CCR or

Command Block

No

Response

Timeout

CCR

CCR

Response

Yes

Character

Timeout

Break

Fault Code

00 Hex
05 Hex

Other

Terminate

Communication

3rd

Try?

1

2

External Device

PLCĆ3

External Device

PLCĆ3

External Device

PLCĆ3

External Device

To Sheet 1

From Sheet 1

ACK

Break

Shift

Character

Invalid

Terminate

Communication

Response Block

No

Yes

Channel

Timeout

Break

Character

Timeout

3rd

Try?

or CCR Response

Out

Timeout

Response

NAK

Terminate

Communication

Are

There

More Blocks

in the

Response

?

Shift

In

Shift

In

Break

Other

No

Yes

3rd

Try?

Terminate

Communication

Terminate

Communication

Terminate

Communication

CCR

PLCĆ3

Yes

No

CCR

Response

Fault Code

00 Hex
05 Hex

Other

Character

Timeout

Break

Terminate

Communication

Will Not Occur During

Multiple Block Responses