Fluid Components Intl ST51A, Installation, Operation & Maintenance Instruction Manual

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OPERATION ST51A/ST75A/ST75AV Mass Flow Meters
58 Fluid Components International LLC
Totalizer Register Description
The instrument’s Modbus interface offers the flow Totalizer value through two different register groups each providing a single precision
floating point data type. Register 5103 offers the flow Totalizer as a single precision floating point value in the Modbus Daniel extension
protocol. Registers 4105 and 4106 offer the flow totalizer as a single precision floating point value in the standard Modbus register form.
Table 20 – ST51A/ST75A/ST75AV Modbus Process Data
Process Variable Values – Daniel Extension
Variable/Parameter Modbus Slave Register Data Type
1
Access
Flow (Value) 5101 Special1 Read
Temp (Value) 5102 Special1 Read
Totalizer (Value) 5103 Special1 Read
K Factor 1 (Value) 5104 Special1 Read/Write
K Factor 2 (Value) 5105 Special1 Read/Write
K Factor 3 (Value) 5106 Special1 Read/Write
Process Variable Values – Integral Registers
Variable/Parameter Modbus Slave Register Data Type
1
Access
Flow MS (Value) 4101 Special2 Read
Flow LS (Value) 4102 Special2 Read
Temperature MS (Value) 4103 Special2 Read
Temperature LS (Value) 4104 Special2 Read
Totalizer MS (Value) 4105 Special2 Read
Totalizer LS (Value) 4106 Special2 Read
K Factor 1_MS 4107 Special2 Read/Write
K Factor 1_LS 4108 Special2 Read/Write
K Factor 2_MS 4109 Special2 Read/Write
K Factor 2_LS 4110 Special2 Read/Write
K Factor3_MS 4111 Special2 Read/Write
K Factor 3_LS 4112 Special2 Read/Write
K Factor 4_MS 4113 Special2 Read/Write
K Factor 4_LS 4114 Special2 Read/Write
Process Variables – Engineering Unit Codes
Variable/Parameter Modbus Slave Register Data Type Access
Flow Eng. Units Code 4020 Integer Read
Temp Eng. Units Code 4021 Integer Read
Totalizer Eng. Units Code 4022 Integer Read
Totalizer Single Precision Floating Point – Service Registers
Variable/Parameter Modbus Slave Register Data Type Access
IROLL MS 4023 Integer Read
IROLL LS 4024 Integer Read
Totalizer_Flag 4026 Integer Read/Write
Device Status Code
Variable/Parameter Modbus Slave Register Data Type Access
Device Status Code
2
4025 Integer Read
Notes: 1. Data Type: Special1 is a collection of discrete registers that contain a 32-bit floating point value, and must be
treated and interpreted as a floating point number by the DCS or the PLC.
Special2 is a collection of discrete registers that contain a 16-bit floating point value, and must be treated and
interpreted as a concatenated floating point number by the DCS or the PLC.
2. Refer to
Table 23
, page 64 for status register bit assignment details.