Emerson 5300, 5400 specifications Common Modbus Host Configuration, Input Registers

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Manual Supplement

00809-0500-4530, Rev AA October 2010

Rosemount 5300/5400 Series

COMMON MODBUS HOST CONFIGURATION

Table 1-12. Byte Transmission Order is specified by the Floating Point Format Code

When using Modbus RTU or Modbus ASCII, the registers to receive status and variables must be configured in the host system.

The transmission of single-precision (4 bytes) IEEE 754 floating point numbers can be rearranged in different byte orders specified by the Floating Point Format Code. The format code information, stated for each Remote Terminal Unit (RTU) respectively, specifies which registers to poll from the 5300/5400 transmitter in order for the RTU to correctly interpret floating point numbers. The byte transmission order for each format code is demonstrated in Table 1-12below.

Format

Byte transmission

Description

Code

order

 

0

[AB] [CD]

Straight word order, most significant byte first

1

[CD] [AB]

Inverse word order, most significant byte first

2

[DC] [BA]

Inverse word order, least significant byte first

3

[BA] [DC]

Straight word order, least significant byte first

 

 

 

Input Registers

NOTE

Some Modbus hosts cannot read the information described here using Input Registers (Modbus function code 4). The Input Register information can also be read using Holding Register (Function code 3). In this case, Input Register number + 5000 is used as Holding Register number.

Between host system and device, it is recommended to use 60 seconds or less between polls, and three retries.

The register area starting with 1300 can be configured to have any of the four format codes. The configuration is done by setting FloatingPointFormatCode register (holding register 3000) to 0-3, as shown in Table 1-12.This configuration can be done with the Rosemount Radar Master program.

NOTE

Depending on the slave number the 5300/5400 transmitter is using, different registers must be used with the default slave number being 1. Slave number is determined by the HART address.

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Contents Manual Supplement Rosemount 5300/5400 Series with Hart to Modbus ConverterExplosions could result in death or serious injury Safety MessagesWorkflow IntroductionMechanical Installation Electrical Installation Field Wiring Connections Hart + RS-485 Bus Installation casesAlternative Multidrop Connection of 5300/5400 Transmitters Star TopologyExternal Hart Devices Slaves No. of devices Approx. update rate SlavesConnect to the MA/MB terminals Establish Hart CommunicationRosemount 5300/5400 Series Connect to the Hart terminals Transmitter Configuration Using RRM to change communication parameters Modbus Communication Protocol ConfigurationModbus Setup Modbus RTU Parameter Configuration Example HMC A44 B4800 PO S2 Levelmaster Communication SetupHMC A127 HMC M2 A2 B9600 D7 PN S1 Levelmaster Parameter Configuration ExampleImplemented Functions of Levelmaster Protocol HMC M1 A246 B9600 D7 PN S1 Modbus Ascii Communication SetupRosemount 5300/5400 Series Alarm Handling Levelmaster Modbus RTUModbus Ascii Rosemount 5300/5400 Series Input Registers Common Modbus Host ConfigurationBit information in bitfield 14. Output Variables for Floating Point Format Code Rosemount 5300/5400 Series Measurement Units Volume LengthEmerson Process Management ROC800 Series Specific Modbus Host ConfigurationABB TotalFlow Emerson Process Management FloBossBristol ControlWave Micro Thermo Electron AutopilotKimray Dacc 2000/3000 ScadaPackNo 5300/5400 communication in RRM Troubleshooting No communication on RS-485 bus MA, MBNo communication with Modbus RTU protocol No communication with Modbus Ascii protocolSelect Enable Modbus Communication and click OK HMC Firmware Upgrade in Rosemount Radar MasterRosemount 5300/5400 Series Click Browse Checksum Rosemount 5300/5400 Series Specifications Rosemount 5300/5400 Series Emerson Process Management Rosemount Measurement