User Manual

Commissioning
Part No.: 4417.762_Rev07 SmartRadar FlexLine
Service Manual 6 - 33
of the original request in the function code field of the response. All
function codes have a most–significant bit (MSB) of 0 (their values
are all below 80 hexadecimal). In an exception response, the
FlexLine device sets the MSB of the function code to 1. This makes
the function code value in an exception response exactly 80 hexa-
decimal higher than the value would be for a normal response. 
With the function code’s MSB set, the master’s application program
can recognize the exception response and can examine the data
field for the exception code.
 Data field:
In a normal response, the FlexLine device may return data or
statistics in the data field (any information that was requested in the
request). In an exception response, the FlexLine device returns an
exception code in the data field. This defines the FlexLine device
condition that caused the exception.
Code Name Meaning
01 Illegal Function The function code received in the query is not an
allowable action for the FlexLine device. This
may be because the function code is only
applicable to newer devices, and was not
implemented in the unit selected. It could also
indicate that the FlexLine device is in the wrong
state to process a request of this type, for
example because it is unconfigured and is being
asked to return register values.
02 Illegal Data Address The data address received in the query is not an
allowable address for the FlexLine device. More
specifically, the combination of reference
number and transfer length is invalid.
03 Illegal Data Value A value contained in the query data field is not
an allowable value for FlexLine device.