Lexicon, Inc.

 

 

 

 

DC-2/MC-1 Serial Communications Protocol

Printed on: 10/19/00

 

 

 

 

 

Data Link Header:

 

 

 

 

Byte Number

Description

 

Value

 

First Byte(0)

 

Start of Packet(SOP)

 

0xF1

 

Byte(1)

 

DLL Data Count

 

nn

 

Application Header:

 

 

 

 

Byte(2)

 

Command

 

nn

 

Byte(3)

 

APP Data Count(number of application data bytes to Follow)

nn

 

Application Data:

 

 

 

 

Byte(4)

 

Data[0]

 

nn

 

Byte(5)

 

Data[1]

 

nn

 

 

Data[…]

 

nn

 

Last Data Byte -1

 

Data[Data Count -1]

 

nn

 

Data Link Tail:

 

 

 

 

Last Byte

 

End of Packet (EOP)

 

0xF2

 

6.1 Errors

If the number of DLL data bytes received is the same as the data count and an EOP has not been received, the DC-2/MC-1 responds by transmitting a NAK packet with an error code DC_ERR_INVALID_PACKET. The DC-2/MC-1 then continues to look for a SOP byte and will not process the erroneous application packet. The HOST can use this as an indicator to retransmit the corrupted packet.

7 Application Layer

7.1 DC-2/MC-1 Asynchronous Notification Packets

DC-2/MC-1 has been designed to transmit the asynchronous notification packets following these system changes:

1.Power On

2.Entering Standby

3.Front Panel Display update and

4.Parameter Value Changes.

The notification packets are defined as follows:

7.1.1 Wakeup Notification

By transmitting the Wakeup Notification, DC-2/MC-1 indicates the unit has just “powered on” or reset and is ready to receive host commands. If no acknowledgment is received within ACK_TIMEOUT, DC-2/MC- 1 will continue to operate. This notification is primarily for the HOST to know the status of the DC-2/MC- 1.

7.1.1.1 Notification Packet Description

Application Header:

Command DC_WAKEUP 0x01

Data Count 00x00

Application Data:

N/A

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ABC Office manual Application Layer, DC-2/MC-1 Asynchronous Notification Packets, Wakeup Notification