Varec 4000 manual Status Bits, Status Bit Data, Exception Responses, Exception Response Reason

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4000

Modbus Implementation

 

 

9.7Status Bits

In the ATT implementation, status bits contain alarms, commands, and status information. The state of a Modbus status bit is defined as either ON (true) or OFF (false). The ON state is represented by a "1". The status bits may be read with function code 1 or 2. They may be written one at a time with function code 5 or multiple bits may be written with function code 15. An example of a read message for bits 2 through 6 as returned by the ATT is shows as follows.

Host Request

Address

Function

Start Reg

Start Reg

# of Reg

# of Reg

Error

 

Code

H

L

H

L

Check

 

 

 

 

 

 

 

01

02

00

02

00

04

XX

 

 

 

 

 

 

 

ATT Response

 

 

 

 

 

Address

Function

Byte

Data

Error

 

 

 

code

Count

 

Check

 

 

 

 

 

 

 

 

 

01

02

01

12

XX

 

 

 

 

 

 

 

 

 

9.7.1Status Bit Data

Binary representation 1 0010 (bits 6-2)

Bit #2: High Advisory Alarm OFF

Bit #3: High Critical Alarm ON

Bit #4: Unauthorized Mass Movement OFF

Bit #5: Standard Density Alarm OFF

Bit #6: Critical Zone Alarm ON

9.8Exception Responses

The exception responses returned by the ATT are listed below:

Exception

Response

Reason

01

Illegal Function

Message is not allowed

 

 

 

02

Illegal Data Address

Data address (bit or register) requested is not defined

 

 

 

03

Illegal Data Value

Data value being written is out of range

 

 

 

04

Busy

During power-up

 

 

 

In addition, messages that are received with a parity error, checksum error, or message format error will be ignored.

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Contents Installation Operations Manual Page Copyright Disclaimer of Warranties Safety Precaution Definitions Safety Precautions Tank Gauge Transmitter Introduction Tank Gauge Transmitter Glossary Tank Gauge Transmitter Viii Introduction Using This ManualConfiguration OperationConstruction Installation Part Number Gauge Adapter Kit Mounting the EquipmentConnecting Input Power WiringATT Wiring Wiring PreparationTerminal Block One TB1 Terminal Block Two TB2 Connecting Host CommunicationTypical EIA485 Wiring ATT EIA485 WiringTypical EIA485 System Wiring Typical Mark/Space Field Wiring ATT Mark/Space WiringInstallation Checkout Connecting the RTDConnecting the Handheld Terminal Wiring CompletionFunction Key Description ConfigurationConfiguration Parameters 1200 Hand Held TerminalTerminal Mode Configuration 1200 Hand Held Terminal Terminal Mode OperationMenu Operation Main Menu Description Main MenuSummary Menu Description Summary MenuConfiguration Menu Description Configuration MenuHost Menu Description Host MenuQuick Setup Imperial Fractional 1900 Quick Setup Defaults General ConfigurationHost Configuration Imperial Decimal 1900 Quick Setup Defaults 3 0-20 Meter 1900 Quick Setup Defaults 4 0-30 Meter 1900 Quick Setup Defaults 8 0-30 Meters 1800 Series Transmitter Quick Setup Imperial Fractional 1800 Series Transmitter Quick SetupImperial Decimal 1800 Series Transmitter Quick Setup 7 0-20 Meters 1800 Series Transmitter Quick SetupImperial Modbus Quick Setup Defaults Metric Modbus Quick Setup Defaults Maintenance and Troubleshooting MaintenanceBattery Replacement Troubleshooting ATT Error Status ConditionsError Message Description ATT Configuration Error Checking ATT Status ConditionsStatus Condition Description Host Communication Loopback Tests Model 1200 Error MessagesEnvironmental SpecificationsSpecifications and Physical Characteristics Input PowerLevel Measurement Agency Acronym Requirement Safety Agency ApprovalsIntrinsic Safety Explosion ProofMajor System Assemblies and Components Assembly/Component Part NumberCommunications Order CodesOrder Codes CPU Board Theory of OperationHost Communications Interfaces Back-up BatteryStatus Inputs and Outputs Atti Communications PortEncoder Battery Backup Temperature MeasurementHost Communication Mark/Space Host Interface Function NumberNumber Exception Compatibility with Varec Tank Polling Unit Modbus Support over Mark/Space Host InterfaceTheory of Operation Model 4040 Display Unit ATT Family of ProductsDigital Inputs Relay SpecificationsModel 4050 Digital Input/Output Unit Digital OutputsModbus Implementation IntroductionImplementation Modbus Implementation Functions and Data Formats Integer RegistersTerm Definition Integer Data Host RequestATT Response Character Data Packed Bit Data Coded DataFloating Point Data Floating-Point RegistersFloating-Point Data Two 16-bit Registers FormatOne 32-bit Register Format Exception Response Reason Status BitsStatus Bit Data Exception ResponsesData Out of Range Loopback TestHardware Implementation Register Number Type Description Integer Register MapRegister Number Sw Ver0-1 Noise Reject Type Status Bit Register Map Floating Point Register MapModbus Implementation 10.3 4000LJFMO Optional Interfaces10.1 4000TIFMO 10.2 4000GEFMO10.6 4000GMFMO 10.5 4000WBFMOAdv Hi Level GlossaryDband TSU Tank Gauge Transmitter 4000 Your official representative Your offical representative