Lexicon MC-12 用户指南

Lexicon 
MC-12 Serial Communications Protocol 

 

Printed on: 07/13/05 

 

7.3.37.2 Data Description 

ParamId: 
 

Data Type: 

Unsigned 16 bit Integer 

Max Value: 

Max Parameter Count as reported by the MC-12 Unit Configuration Response 
Packet in 7.3.39.2

 
ParamType: 

PARAM_TYPE_UINT8 

0 

Unsigned 8 bit integer(0 to 
255) 

1 

PARAM_TYPE_UINT16 

1 

Unsigned 8 bit integer(0 to 
65535) 

2 

PARAM_TYPE_CSTR8 

2 

Zero terminated string of 8 
ascii characters 

9 

PARAM_TYPE_CSTR13 

3 

Zero terminated string of 13 
ascii characters 

14 

PARAM_TYPE_UINT32 

4 

Unsigned 32 bit integer (0 to 
4,294,967,295 ) 

4 

PARAM_TYPE_BOOLEAN 

5 

Boolean (0 to 1) 

1 

PARAM_TYPE_INT8 

6 

Signed 8 bit integer  
(-127 to 128) 

1 

PARAM_TYPE_BRANCH 7 

Parameter 

Branch 

N/A 

PARAM_TYPE_INT16 

8 

Signed 16 bit integer  
(-32,767 to 32,768) 

2 

PARAM_TYPE_CSTR20 

9 

Zero terminated string of 20 
ascii characters 

21 

 
Value: 
 

The data value transmitted is dependent on the ParamType, as described above.  The 
Data Value is always packed starting at the Value[0] byte in the packet.  For multi-byte 
data, the values are packed LSB first(Value[0]) to MSB(Value[0+(num bytes-1)]).  For 
example:  Setting a given signed 16 bit parameter to a value of -300 the data array would 
be packed as follows: 

 

 
Value[0] = 0xd4 
Value[1] = 0xfe 

 

Value[2 - 13] = don't care. 

 

All signed values are in the 2's compliment format. 

 
 

7.3.37.3 Data Validation: 

The ParamId must be a valid Parameter.  The ParamType must be valid for the given ParamId. If either of 
these condition is not true the MC-12 will respond with a NAK packet and error code DC _ 
INVALID_PARAM_ID.  The data value size cannot exceed the size of a given data type.  A value that 
does exceed the size of a give data type will be truncated to the appropriate size.  The ParamType 
transmitted must match the ParamType for the Parameter being transmitted, as per the Parameter Definition 
as transmitted by the MC_SYS_PARAM_DEF_PKT .  If the types do not match The MC-12 will transmit 

© 2005 Harman Specialty Group All rights reserved. 

 

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