Figure 42 - Mt100 Configuration Software Modbus Tab, Serial Interface Configuration; Table 14 - Mt100 Modbus Function Codes - FCI MT100 Installation, Operation And Maintenance Manual

MT100 Multipoint Flow Meter
Click the Modbus tab and configure the serial interface parameters (Node ID, Mode, Baud, Data Bits, Parity, and Stop Bits) as required for
your application. Then click Send to Device to program the MT100 (enter "2772" user password). Refer to the MT100 Configuration
Software manual 06EN003461 for details on digital bus configuration and general operation information.
Figure 42 – MT100 Configuration Software Modbus Tab, Serial Interface Configuration
MT100 Modbus Commands
With the Modbus protocol the instrument data is read and written via multiple register access. The following public function numbers are
defined for communication with the MT100: 03 and 04.
Function Code
MT100 Process Data Registers
Two data type registers are set up in the MT100 to access the process data. One uses integer data registers (4000) and the other uses the
Daniel extension data registers (5000).
All designated registers must be read for each variable value to extract the floating-point number. Conversion must be started manually
with the 4000 registers. The Daniel extension handles the read and conversion automatically. To use the Daniel extension the master must
support the Daniel extension function.
Totalizer Description
The MT100 through the Modbus channel offers the flow Totalizer value through three different register groups organized into two forms of
floating point data types. Registers 5103 and 5104, offer the flow Totalizer as a double precision floating point value in the Modbus Daniel
extension protocol. Registers 4105, 4106, 4107, and 4108 offer the flow Totalizer as a double precision floating point value in the Modbus
standard integer register form. And lastly registers 4111, 4112, 4113, and 4114 offer the flow totalizer as a single precision floating point
value in the Modbus standard register form. Because the Totalizer values can become a very large number, the single precision floating
point presents the data as two register groups. Group 1 called TOTALIZER 1 holds the lower count with a defaulted count limit of
65,535.996. TOTALIZER 1 resets back to zero when the count limit is reached. Group 2 called TOTALIZER 2 holds the upper count and it
Fluid Components International LLC
Table 14 – MT100 Modbus Function Codes
03
04
Function Description
Holding Register Read Only – Process Data
Holding Register Read/Write – Service Data
Read Input Register for all Process Data
Read Input Register for all Service "Start/Stop" Totalizer
OPERATION
75