Sierra InnovaSonic 205i, Instruction Manual

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10
Most commercially available Modbus host software uses a register format. See Modbus.org for more details. This
format is much easier to use. By using the 40000 registers, function code Ox 03 is automatically used for reads
and function code Ox 06 is automatically used for single register writes. The CRC checksum is also automatically
calculated and added to the data frame, as well as verified on the returned data frame. Error codes are received and
decoded.
Modbus host software also allows for easy decoding of the data. The 205i uses the following data types:
32 bits real: Float or IEE754 (LSB-MSB byte order)
32 bits int.: 32 bit un-signed integer. Allows for a number from 0 to 4,294,967,295 (LSB-MSB byte order)
16 bits int: 16 bit signed integer. This allow for a number between -65,535 and +65,534
String: 8 bit ASCII characters, 2 per 16 bit register.
PDU
Address
Register Read Write Type No. Registers*
$0000 40001 Flow/s - low word 32 bits real 2
$0001 40002 Flow/s - high word
$0002 40003 Flow/m - low word 32 bits real 2
$0003 40004 Flow/m- high word
$0004 40005 Flow/h - low word 32 bits real 2
$0005 40006 Flow/h - high word
$0006 40007 Velocity – low word 32 bits real 2
$0007 40008 Velocity – high word
$0008 40009 Positive total – low word 32 bits int. 2
$0009 40010 Positive total – high word
$000A 40011 Positive total – exponent 16 bits int. 1
$000B 40012 Negative total – low word 32 bits int. 2
$000C 40013 Negative total – high word
$000D 40014 Negative total – exponent 16 bits int. 1
$000E 40015 Net total – low word 32 bits int. 2
$000F 40016 Net total – high word
$0010 40017 Net total – exponent 16 bits int. 1
$0011 40018 Energy total – low word 32 bits int. 2