InsiteIG MPA-48, Manual

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8
Exception Responses
If the MPA-48 analyzer receives a query without a communication error, but cannot handle it, an
exception response will be returned.
In a normal response, the MPA-48 echoes the function code of the original query in the function code
field of the response. In an exception response, the MPA-48 sets the MSB of the function code to 1.
This makes the function code value in an exception response exactly 80 hexadecimal higher than the
value would be for a normal response.
The data field in an exception response contains an exception code. The exception codes supported
by the MPA-48 are:
Exception code Description
01 Illegal function code
02 Illegal data address