Sierra 240-VTP, 241-VTP instruction manual Following registers contain the display units strings

Series 24-HP Instruction Manual Appendix E MODBUS Commands

The following registers contain the display units strings:

Registers

32007-32012

32001-32006

32025-32030

32019-32024

32031-32036

32013-32017

Variable

Volume flow units Mass flow units Temperature units Pressure units

Density units Energy flow units

Data type	Units	Function code
string	—	03, 04
string	—	03, 04
string	—	03, 04
string		03, 04
	—
string	—	03, 04
string	—	03, 04

Addresses 2006-2011 2000-2005 2024-2029 2018-2023

2030-2035

2012-2017

Function codes 03 (read holding registers) and 04 (read input regis- ters) are the only codes supported for reading these registers, and function codes for writing holding registers are not implemented. We recommend that the floating point and long integer registers be read in a single operation with the number of registers being a mul- tiple of two. If these data are read in two separate operations, each reading a single 16-bit register, then the value will likely be invalid.

The floating point registers with values in display units are scaled to the same units as are displayed, but are instantaneous values that are not smoothed. If display smoothing is enabled (non-zero value entered in the Display TC item in the Display Menu), then the register values will not agree exactly with the displayed val- ues.

Exception Status Definitions

The Read Exception Status command (function code 07) returns the exception status byte, which is defined as follows. This byte may be cleared by setting “coil” register #00003 (function code 5, address 2, data = 0xff00).

Bit(s)	Definition
0-1	Byte order (see Modbus Order on page 2)
	0 = 3-2:1-0 1 = 2-3:0-1
	2 = 1-0:3-2 3 = 0-1:2-3

2Temperature sensor fault

3 Pressure sensor fault

4 A/D converter fault

5 Period overflow

6 Pulse overflow

7 Configuration changed

IM-24-HP E-5