GASSONIC Observer-i - 6.5.1. Exception Responses; 6.5.2. Exception Code Field

GASSONIC OBSERVER-i
55
6.5.1. Exception Responses
Byte Modbus Range
Referenced to Gassonic
Observer-i
1
st
Slave Address 1-247* (Decimal) Gassonic Observer-i ID (Address)
2
nd
Function Code 83 or 86 (Hex) MSB is set with Function Code
3
rd
Exception Code 01 - 06 (Hex) Appropriate Exception Code (See
below)
4
th
CRC Lo 00-FF (Hex) CRC Lo Byte
5
th
CRC Hi 00-FF (Hex) CRC Hi Byte
Table 10: Exception responses
6.5.2. Exception Code Field
In a normal response, the Gassonic Observer-i returns data and status in the data field, requested in
the query from the master. In an exception response, the Gassonic Observer-i returns an exception
code in the data field, which describes the condition that caused the exception. Below is a list of
exception codes that are supported by the Gassonic Observer-i:
Code Name Description
01 Illegal Function The function code received in the query is not an
allowable action for the Gassonic Observer-i.
02 Illegal Data Address The data address received in the query is not an
allowable address for the Gassonic Observer-i.
03 Illegal Data Value A value contained in the query data field is not an
allowable value for the Gassonic Observer-i.
04 Slave Device Failure An unrecoverable error occurred while the
Gassonic Observer-i was attempting to perform the
requested action.
05 Acknowledge The Gassonic Observer-i has accepted the request
and is processing it, but a long duration of time will
be required. This response is returned to prevent a
timeout error from occurring in the master.
06 Device Busy The Gassonic Observer-i is engaged in processing
a long-duration program command. The master
should retransmit the message later when the slave
is free.
Table 11: Exception Code Field