Holding Registers
Device Name:
A string, up to 40 characters long, that will be displayed on the LCD (if
present). When reading or writing, all 20 registers must be requested. Strings less than
40 characters shall be 0 padded.
Velocity Unit:
Selects the unit of velocity for the value in the velocity register. See
Table 1.
Flow Unit:
Selects the unit of flow for the value in the Flow register. See Table 2.
Volume Unit:
Selects the unit of volume for the value in the Total Flow register. See
Table 3.
Reset Total Flow:
When a value of 1 is written to this register, the value in the Total
Flow register is reset to 0. Writing a value of 0 has no effect. This register will always
return a 0 when read.
Reset Device:
When a value of 1 is written to this register, the device will perform a
warm reset after 5 seconds. Writing a value of 0 has no effect. This register will always
return 0 when read.
* Default unit
Multi-Address Support
Multi-Address support allows a register to be read or written to using different byte
orientations specified by the address range. For example, input register 0003 can
also be read at 2003, 4003 and 6003 with different byte orientations as listed in Table
7. Registers that do not have multi-address support are only available in Big-Endian
byte orientation (Modbus
®
standard).
Register
Description
Data Type
Range
0001 – 0020
0021
0022
0023
0024
0025
Device Name
Velocity Unit
Flow Unit
Volume Unit
Reset Total Flow
Reset Device
String
Unsigned 16bit integer
Unsigned 16bit integer
Unsigned 16bit integer
Unsigned 16bit integer
Unsigned 16bit integer
0 – 7
0 – 15
0 – 3
0 or 1
0 or 1
Float/32bit Values
16Bit Values
Register 1
Register 2
Register 3
Byte Order
Address Range MSB
LSB
MSB
LSB
Big-Endian
Byte Swap
Word Swap
Little-Endian
1-2000
2001-4000
4001-6000
6001-8000
A
B
C
D
B
A
D
C
C
D
A
B
D
C
B
A
A
B
A
B
B
A
B
A
TABLE 1: VELOCITY UNIT VALUES
Value Unit
*0
1
2
3
4
5
6
7
Feet-per-second (ft/s)
Feet-per-minute (ft/min)
Feet-per-hour (ft/hr)
Feet-per-day (ft/day)
Meters-per-second (m/s)
Meters-per-minute (m/min)
Meters-per-hour (m/hr)
Meters-per-day (m/day)
TABLE 2: FLOW UNIT VALUES
Value Unit
*0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Cubic-feet-per-second (ft
3
/s)
Cubic-feet-per-minute (ft
3
/min)
Cubic-feet-per-hour (ft
3
/hr)
Cubic-feet-per-day (ft
3
/day)
Gallons-per-second (gal/s)
Gallons-per-minute (gal/min)
Gallons-per-hour (gal/hr)
Gallons-per-day (gal/day)
Liters-per-second (L/s)
Liters-per-minute (L/min)
Liters-per-hour (L/hr)
Liters-per-day (L/day)
Cubic-meters-per-second (m
3
/s)
Cubic-meters-per-minute (m
3
/min)
Cubic-meters-per-minute (m
3
/min)
Cubic-meters-per-day (m3/day)
TABLE 3: VOLUME UNIT VALUES
Value Unit
0
*1
2
3
Cubic-feet (ft
3
)
Gallons (gal)
Liters (L)
Cubic-meters (m3)
