In-Cabinet Distributed I/O

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1794 FLEX I/O

HART Smart Instrumentation

HART (Highway Addressable Remote Transmitter) is an open protocol designed to connect analog devices. For HART connectivity, select from products available from Rockwell Automation and our Encompass partners.

Select a HART Interface

For Your Application	Select	Description
Analog and HART in one module Instrumentation in hazardous locations (FLEX Ex modules) Supports FDT-compatible asset management software to HART devices using provided DTMs HART commands can be transmitted as unscheduled messages	1794 FLEX I/O 1797 FLEX Ex I/O	FLEX I/O and FLEX Ex modules designed for distributed HART systems.
Analog and HART connectivity in one module No external hardware required to access HART signal HART commands can be transmitted as unscheduled messages Supports asset management software to HART device	1756-IF8H 1756-OF8H	Rockwell Automation analog I/O modules for use in ControlLogix chassis
Data acquisition or control application with slow update requirements (such as a tank farm) No external hardware required to access HART signal Does not connect directly to asset management software	MVI56-HART	Prosoft interface

HART Interface Modules

FLEX and FLEX Ex HART analog modules are ideal for use in applications that need connection with FDT (Field Device Tool) compatible asset management software, such as the Rockwell Software FieldCare HART Communication bundle or Endress + Hauser Fieldcare. For HART Device Type Management (DTM) programs and drivers, go to http://www.ab.com/io/downloads.html and select HART DTM files.

• FLEX HART analog modules can be used on ControlNet or EtherNet/IP. The FLEX Ethernet adapter requires firmware v3.1, which is flash upgradeable, to support these modules.
  
• Each HART field device is wired to its own input or output channel:
  
  • 8 single-ended channels
    
  • does not support multi-drop
    
  • 2- or 3-wire devices
    
• For use with FlexLogix, the modules must be used on distributed rail with ControlNet adapter and not on local rail.
  
• HART commands can be transmitted by unscheduled message:
  
  • sample RLL subroutines available
    
  • currently limited to one instance of RLL subroutine per module, one channel at a time
    

HART Analog Input Module

Cat. No.	Number of Inputs	Signal Range	Input Conversion Rate	Input Resolution	Absolute Accuracy	Step Response to 99%	External DC Supply Current, Nom.	Power Dissipation, Max.	Terminal Base Unit
1794-IE8H	8 single-ended Non-isolated	4…20 mA	10 ms (50 Hz) / 8.33 ms (60 Hz)	16 bits	0.1% Full Scale at 20 °C (68 °F)	80 ms (current terminal)	190 mA at 24V DC	3.9 W at 31.2V DC	1794-TB3G or 1794-TB3GS
1794-IF8IH	8 single-ended Isolated	4…20 mA (user configurable) 0…20 mA (user configurable)	—	16 bits - unipolar; 15 bits + sign - bipolar 0.320 mA/cnt unipolar; 0.640 mA/cnt bipolar	0.1% Full Scale at 25 °C	4.17 Hz conversion rate = 480 ms 10.0 Hz conversion rate = 200 ms 16.7 Hz conversion rate = 120 ms 19.6 Hz conversion rate = 101 ms 62 Hz conversion rate = 32 ms 470 Hz conversion rate = 4 ms	190 mA at 24V DC	4.8 W at 31.2V DC	1794-TB3 or 1794-TB3S

HART Analog Output Module

Cat. No.	Number of Outputs	Signal Range	Output Conversion Rate	Output Resolution	Absolute Accuracy	Step Response to 99%	External DC Supply Current, Nom.	Power Dissipation, Max.	Terminal Base Unit
1794-OE8H	8 single-ended Non-isolated	4…20 mA 0…20 mA	10 ms for all channels	13 bits	0.1% Full Scale at 20 °C (68 °F)	13 ms to 99% of FS / 115 ms during HART comms	190 mA at 24V DC	6.1 W at 31.2V DC	1794-TB3G or 1794-TB3GS
1794-OF8IH	8 single-ended Isolated	4…20 mA (user configurable) 0…20 mA (user configurable)	10 ms	16 bits - unipolar 0.305 mA/cnt unipolar	± 0.1% Full Scale at 25 °C ± 0.35% Full Scale at 0…55 °C	—	450 mA at 24V DC	5.0 W at 31.2V DC	1794-TB3 or 1794-TB3S