User manual

IEC61131 User and Reference Manual
April 22, 2008
309
HART Device Response Codes
The code output of the function block contains the response code from the HART device
contains communication error and status information. The information varies by device, but
there are some common values.
If bit 7 of the high byte is set, the high byte contains a communication error summary. This
field is bit-mapped. The following table shows the meaning of each bit as defined by the
HART protocol specifications. Consult the documentation for the HART device for more
information.
Bit
Description
6
vertical parity error
5
overrun error
4
framing error
3
longitudinal parity error
2
reserved – always 0
1
buffer overflow
0
undefined
If bit 7 of the high byte is cleared, the high byte contains a command response summary.
The following table shows common values. Other values may be defined for specific
commands. Consult the documentation for the HART device.
Code
Description
32
Busy – the device is performing a function that
cannot be interrupted by this command
64
Command not Implemented – the command is not
defined for this device.
The low byte contains the field device status. This field is bit-mapped. The following table
shows the meaning of each bit as defined by the HART protocol specifications. Consult the
documentation for the HART device for more information.
Bit
Description
7
field device malfunction
6
Configuration changed
5
cold start
4
more status available (use command 48 to read)
3
primary variable analog output fixed
2
primary variable analog output saturated
1
non-primary variable out of limits
0
primary variable out of limits