38
Rockwell Automation Publication 1718-UM001A-EN-E - December 2019
Appendix C
Additional HART Protocol Information
If no error was detected in the outgoing communication, the second byte
contains status information pertaining to the operational state of the field or slave
device.
0
10
Applied Process Too Low - Lower Range Value Too Low - MultiDrop Not Supported
0
11
In MultiDrop Mode - Invalid Transmitter Variable Code - Upper Range Value Too High
0
12
Invalid Unit Code - Upper Range Value Too Low
0
13
Both Range Values Out of Limits
0
14
Pushed Upper Range Value Over Limit - Span Too Small
0
16
Access restricted
0
32
Device busy
0
64
Command not implemented
Table 1 - Response Codes and Field Device Status (Continued)
Response Code
Description
If Bit 7 is
And Bits
6…0 are
Table 2 - Field Device Status Bit Mask Definitions
Bit
Bit Mask
Definition
7
16#80
Device malfunction - The device detected a serious error or failure that compromises device operation
6
16#40
Configuration changed - An operation was performed that changed the device’s configuration
5
16#20
Cold start - A power failure or device reset occurred
4
16#10
More status available - More status information is available via command 48, Read Additional Status Information
3
16#08
Loop current fixed - The loop current is being held at a fixed value and is not responding to process variations
2
16#04
Loop current saturated - The loop current has reached its upper or lower endpoint limit and cannot increase or decrease any further
1
16#02
Non-primary variable out of limits - A device variable not mapped to the PV is beyond its operating limits
0
16#01
Primary variable out of limits - The PV is beyond its operating limit
IMPORTANT
The 16# means this number is Hex display style.
Table 3 - HART Universal Commands
Command
Data in Command
Data in Reply
Contained in
No.
Function
Byte
Data
Type
(1)
Byte
Data
Type
Input
Tag
CIP
MSG
0
Read Unique
Identified
None
0
1
2
3
4
5
6
7
8
9…11
254 (expansion)
Manufacturer identification code
Manufacturer device type code
Number of preambles required
Universal command revision
Device-specific command revision
Software revision
Hardware revision
Device function flags
(2)
Device ID number
(H)
(B)
x
x
x
x
x
x
x
x
x
x
1
Read primary
variable
0
1…4
PV units code
Primary variable
(F)
x
x
x
2
Read current and
percent of range
None
0…3
4…7
Current (mA)
Primary variable %
(F)
(F)
x
x
x
x
