Hoffer Flow Controls HIT-4L, User Manual

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Modbus Communications 37
HIT-4L HP-329
6. MODBUS COMMUNICATIONS
HIT Com Software or a Modbus Master may be used to configure HIT-
4L, monitor process variables and obtain diagnostic information from
the HIT-4L.
Supported Commands
Function Code
(Hex)
Description
03 Read holding registers
05 Preset Boolean (for Enron event record
acknowledgement
10 Write Commands
Data Types
Data Type Byte Count Register Count
Unsigned Int (U16) 2 1
Unsigned Int (U32) 4 1
Floating Point (FP32) 4 *1 or 2
Double Precision Float (FP64) 8 *1 or 4
* The variables Rate, Total and Grand Total, Temperature, Pressure
and Density are available as single 32 or 64-bit registers as well as
multiple 16-bit registers.
Registers
Each register is labeled as Read Only (RO) or Read/Write (R/W)
according to access type.
Register
(Decimal)
Description Data
Type
Access Notes
1 Clear Event Logs U16 RO
3 Clear Hourly
Logs
U16 RO
5 Clear Daily Logs U16 RO
7 Clear Grand
Total
U16 RO
9 Clear Total U16 RO Send a read request to
this register to clear
Total
32 Request Event
Logs
U16
(2)
FP32
(4)
RO