
PLX51-HART-4I / PLX51-HART-4O
♦
HART Input/Output
Operation
Multidrop Field Devices
User Manual
ProSoft Technology, Inc.
Page 73 of 127
4.4.1 Multidrop
When multidrop is being used for HART devices the data from each device will
automatically be updated to the specific Multidrop Device Index (MD). The table
below indicates the Modbus location for the associated data.
Figure 4.12 - Setting Multidrop Device Index
Table 4.15 - Modbus Multidrop Register Map
Register Type:
Holding Registers
Parameter
Byte
Length
Date
Type
Register
General
Channel
0
Channel
1
Channel
2
Channel
3
Multidrop Device Index (MD) - 0
Poll Status
Bit 0 – Online
When set this bit will
indicate that the device is
online
2
INT
1000
2000
3000
4000
Manufacturer ID
1
BYTE
-
1001
2001
3001
4001
Mfg Device Type Code
1
BYTE
-
Number of Preambles
Required
1
BYTE
-
1002
2002
3002
4002
Universal Command Rev
1
BYTE
-
Device Specific Command
Rev
1
BYTE
-
1003
2003
3003
4003
Software Rev
1
BYTE
-
Hardware Rev
1
BYTE
-
1004
2004
3004
4004
Device Function Flags
1
BYTE
-
Device ID Number
3
BYTE[3]
-
1005
2005
3005
4005
Pad Byte
1
BYTE
-
Preamble Response
1
BYTE
-
1007
2007
3007
4007
Max Number of Device Vars 1
BYTE
-
Config Change Count
2
INT
-
1008
2008
3008
4008
Extended Device Status
1
BYTE
-
1009
2009
3009
4009
Pad Byte
1
BYTE
-
Sensor Serial Number
3
BYTE[3]
-
1010
2010
3010
4010
Units Code for Sensor
1
BYTE
-
Sensor Upper Limit
4
REAL
-
1012
2012
3012
4012
Sensor Lower Limit
4
REAL
-
1014
2014
3014
4014
Sensor Minimum Span
4
REAL
-
1016
2016
3016
4016
Tag
8
BYTE[8]
-
1018
2018
3018
4018