SMSC manual COM20020 Operation

Reconfigure Timer has

Timed Out

Power On

Send

Reconfigure

Burst

Read Node ID

Write ID to

RAM Buffer

1

Set NID=ID

Start

Y

Invitation

N

Reconfiguration

to Transmit to

Timer (840 mS)

this ID?

N

Y

Y

Free Buffer

N

TA?

Enquiry to

this ID?

Y

N

Transmit

Y

N

SOH?

NAK

RI?

Y

N

RI?

Transmit

Write SID

Broadcast?

ACK

No Activity

N

to Buffer

N

Transmit

for 82

uS?

Y

Free Buffer

Send

Enquiry

No

Y

DID

Y

Y

=0?

Packet

Activity

N

for 74.7

Set NID=ID

N

N

Y

N

us?

Broadcast

ACK?

DID

Enabled?

Start Timer:

Y

Y

N

=ID?

Y

Was Packet

Set TA

Y

N

T=(255-ID)

Broadcast?

NAK?

x 146 us

N

1

Write Buffer

with Packet

Activity

Y

No

On Line?

Pass the

Y

Set TA

Activity

Token

N

for 74.7

us?

N

CRC

N

N

T=0?

No

OK?

Increment

Y

N

Y

Activity

N

Y

NID

Y

for 74.7

Set TMA

ACK?

us?

N

LENGTH

OK?

Y

Y

	ID refers to the identification number of the ID assigned to this node.	DID		Set RI
-		=0?
-	NID refers to the next identification number that receives the token after	N
	after this ID passes it.	DID	N
-	SID refers to the source identification.
-	DID refers to the destination identification.	=ID?
-	SOH refers to the start of header character; preceeds all data packets.	Y
		SEND ACK

FIGURE 1 - COM20020 OPERATION

7