Varec 4000 manual ATT EIA485 Wiring, Typical EIA485 Wiring

Page 17

4000

Installation

 

 

2.4.5ATT EIA485 Wiring

The ATT uses a 2-wire EIA485 hardware interface to communicate with the Modbus master. EIA485 is a high speed differential communications network which allows up to 32 devices to operate on one network. The ATT and Modbus master share a twisted pair of wires to communicate. Figure 2-4 illustrates the typical EIA485 wiring.

The communication distance that EIA485 can reliably travel is dependent on baud rate (communication speed), wire quality, environmental noise, wiring configuration, and the number of multi-dropped ATTs. The recommended wire for EIA485 systems is 18-gauge or larger, shielded, twisted pairs. The shield should be earth grounded at the Modbus master (control system or computer end). The shield at the ATT should be open. The ATT B- power line acts as a common reference tie to the Modbus master. Figure 2-5 on page 8 illustrates the EIA485 Modbus system.

 

 

TB2

 

 

TB2

 

Power Supply

6

 

 

5

+48

 

VDC

Common

 

4

 

 

 

RTU 8130 with 8230 expansion module

Figure 2-4: Typical EIA485 Wiring

7

Image 17
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 ManualConstruction ConfigurationOperation Installation Part Number Gauge Adapter Kit Mounting the EquipmentATT Wiring WiringWiring Preparation Connecting Input PowerTerminal 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 WiringConnecting the Handheld Terminal Connecting the RTDWiring Completion Installation CheckoutConfiguration Parameters Configuration1200 Hand Held Terminal Function Key DescriptionTerminal 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 Host Configuration Imperial Fractional 1900 Quick Setup DefaultsGeneral Configuration Imperial Decimal 1900 Quick Setup Defaults 3 0-20 Meter 1900 Quick Setup Defaults 4 0-30 Meter 1900 Quick Setup Defaults Imperial Decimal 1800 Series Transmitter Quick Setup Imperial Fractional 1800 Series Transmitter Quick Setup7 0-20 Meters 1800 Series Transmitter Quick Setup 8 0-30 Meters 1800 Series Transmitter Quick SetupImperial Modbus Quick Setup Defaults Metric Modbus Quick Setup Defaults Battery Replacement Maintenance and TroubleshootingMaintenance Error Message Description TroubleshootingATT Error Status Conditions Status Condition Description ATT Configuration Error CheckingATT Status Conditions Host Communication Loopback Tests Model 1200 Error MessagesSpecifications and Physical Characteristics SpecificationsInput Power EnvironmentalLevel Measurement Intrinsic Safety Safety Agency ApprovalsExplosion Proof Agency Acronym RequirementMajor System Assemblies and Components Assembly/Component Part NumberCommunications Order CodesOrder Codes CPU Board Theory of OperationStatus Inputs and Outputs Back-up BatteryAtti Communications Port Host Communications InterfacesHost Communication Encoder Battery BackupTemperature Measurement Number Exception Mark/Space Host InterfaceFunction Number Compatibility with Varec Tank Polling Unit Modbus Support over Mark/Space Host InterfaceTheory of Operation Model 4040 Display Unit ATT Family of ProductsModel 4050 Digital Input/Output Unit Relay SpecificationsDigital Outputs Digital InputsImplementation Modbus ImplementationIntroduction Modbus Implementation Term Definition Functions and Data FormatsInteger Registers ATT Response Integer DataHost Request Character Data Packed Bit Data Coded DataFloating-Point Data Floating-Point RegistersTwo 16-bit Registers Format Floating Point DataOne 32-bit Register Format Status Bit Data Status BitsException Responses Exception Response ReasonHardware Implementation Data Out of RangeLoopback Test Register Number Type Description Integer Register MapRegister Number Sw Ver0-1 Noise Reject Type Status Bit Register Map Floating Point Register MapModbus Implementation 10.1 4000TIFMO Optional Interfaces10.2 4000GEFMO 10.3 4000LJFMO10.6 4000GMFMO 10.5 4000WBFMOAdv Hi Level GlossaryDband TSU Tank Gauge Transmitter 4000 Your official representative Your offical representative