Installation, Operation and Maintenance Manual
MDE 254 Rev. 1 March 2021
HART Command Set 19
Section 8: HART Command Set
Byte Format Description
33 Unsigned-8 Slot 4: Device Variable Code (see Section 9.1)
34 Enum Slot 4: Device Variable Classification (see Section 8.4, Table 131)
35 Enum Slot 4: Units Code (see Section 8.4, Table120)
36 - 39 Float Slot 4: Device Variable Value
40 Bits Slot 4: Device Variable Status (see Section 9.2)
41 Unsigned-8 Slot 5: Device Variable Code (see Section 9.1)
42 Enum Slot 5: Device Variable Classification (see Section 8.4, Table 131)
43 Enum Slot 5: Units Code (see Section 8.4, Table 120)
44 - 47 Float Slot 5: Device Variable Value
48 Bits Slot 5: Device Variable Status (see Section 9.2)
49 Unsigned-8 Slot 6: Device Variable Code (see Section 9.1)
50 Enum Slot 6: Device Variable Classification (see Section 8.4, Table 131)
51 Enum Slot 6: Units Code (see Section 8.4, Table 120)
52 - 55 Float Slot 6: Device Variable Value
56 Bits Slot 6: Device Variable Status (see Section 9.2)
57 Unsigned-8 Slot 7: Device Variable Code (see Section 9.1)
58 Enum Slot 7: Device Variable Classification (see Section 8.4, Table 131)
59 Enum Slot 7: Units Code (see Section 8.4, Table 120)
60 - 63 Float Slot 7: Device Variable Value
64 Bits Slot 7: Device Variable Status (see Section 9.2)
65 - 68 Time Slot 0: Data Time Stamp
Table 31. Command-Specific Response Codes
Code Class Description
0 Success No Command-Specific Errors
1 Undefined
2 Error Invalid Selection
3 - 4 Undefined
5 Error Too Few Data Bytes Received
6 Error Device-Specific Command Error
7 Undefined
8 Warning Update Failure
9 - 13 Undefined
14 Warning Dynamic Variables Returned for Device Variables
15 Undefined
16 Error Access Restricted
17 - 29 Undefined
30 Warning Command Response Truncated
31 - 127 Undefined