Rockwell Automation 1770-HT8 SMART TRANSMITTER User Manual

Page 17

Introducing the Smart Transmitter

Chapter 1
Interface

1-6

Full Duplex Communications

With DF1 full duplex systems, you can communicate directly to a single
Smart Transmitter Interface. No programmable controllers are
necessary—just a computer running the appropriate software, the HART
field devices, and the Smart Transmitter Interface between them. The host
computer and the Smart Transmitter Interface should be connected with
either an RS-232 cable for distances equal to or less than 50 feet, or two
modems for distances greater than 50 feet. (See Figure 1.6 and Figure 1.7.)
This gives end users with less complex applications, inexpensive access to
HART field devices and to the advantages of the HART protocol.

Figure 1.6

Full Duplex Communication with no Modem

90050

HART

Field

Devices

RS-232 CABLE

HOST COMPUTER

Smart

Transmitter

Interface

Figure 1.7

Full Duplex with Modems

90049