Output, Description – National Instruments CAN 372139B-01 User Manual

Page 178

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Chapter 6

Automotive Diagnostic Command Set API for C

Automotive Diagnostic Command Set User Manual

6-14

ni.com

Output

dataOut

Points to the byte array to be filled with the binary representation of

value

.

len

On input,

len

must contain the

dataOut

array length. On return, it contains the number

of valid data bytes in the

dataOut

array.

Description

Data input to diagnostic services (for example,

ndWriteDataByLocalIdentifier

) is

usually a byte array of binary data. If you have the data input description (for example, byte
3 and 4 are engine RPM scaled as .25 *

×

RPM in Motorola representation), you can use

ndConvertFromPhys

to convert the physical value to the byte stream by filling an

appropriate

typeDescriptor

struct.

ndConvertFromPhys

converts only the portion specified by one type descriptor to a binary

representation. If your data input consists of several values, you can use

ndConvertFromPhys

multiple times on different parts of the byte array.

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