Dwyer Instruments IEF Series Operating Instruction page 6

Holding Registers
Register Description
0001 – 0020 Device Name
0021
Velocity Unit
0022 Flow Unit
0023
Volume Unit
0024 Reset Total Flow
0025 Reset Device
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.
TABLE 1: VELOCITY UNIT VALUES
Value Unit
*0 Feet-per-second (ft/s)
1 Feet-per-minute (ft/min)
2 Feet-per-hour (ft/hr)
3 Feet-per-day (ft/day)
4 Meters-per-second (m/s)
5 Meters-per-minute (m/min)
6 Meters-per-hour (m/hr)
7 Meters-per-day (m/day)
TABLE 2: FLOW UNIT VALUES
Value Unit
*0 Cubic-feet-per-second (ft
3
1 Cubic-feet-per-minute (ft
3
2 Cubic-feet-per-hour (ft /hr)
3
3 Cubic-feet-per-day (ft /day)
3
4
Gallons-per-second (gal/s)
5 Gallons-per-minute (gal/min)
6
Gallons-per-hour (gal/hr)
7 Gallons-per-day (gal/day)
8 Liters-per-second (L/s)
9 Liters-per-minute (L/min)
10 Liters-per-hour (L/hr)
11 Liters-per-day (L/day)
12 Cubic-meters-per-second (m
13 Cubic-meters-per-minute (m
14 Cubic-meters-per-minute (m
15 Cubic-meters-per-day (m3/day)
TABLE 3: VOLUME UNIT VALUES
Value Unit
0 Cubic-feet (ft )
3
*1 Gallons (gal)
2 Liters (L)
3 Cubic-meters (m3)
* Default unit
Data Type Range
String
Unsigned 16bit integer 0 – 7
Unsigned 16bit integer 0 – 15
Unsigned 16bit integer 0 – 3
Unsigned 16bit integer 0 or 1
Unsigned 16bit integer 0 or 1
/s)
/min)
/s)
3
/min)
3
/min)
3
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).
®
Byte Order Address Range
Big-Endian 1-2000
Byte Swap 2001-4000
Word Swap 4001-6000
Little-Endian 6001-8000
Float/32bit Values 16Bit Values
Register 1 Register 2 Register 3
MSB LSB MSB
A B C D A
B A D C B
C D A B A
D C B A B
LSB
B
A
B
A