Siemens S7-300 - Deactivate One Channel of a Channel Pair for 1 Oo1 Evaluation; HART Basics; What Is HART; Properties of HART

Analog modules
9.3 SM 336; F-AI 6 x 0/4 ... 20 mA HART
Fail-safe signal modules
278 Installation and Operating Manual, 01/2010, A5E00085586-10
9.3.15.3 Deactivate one channel of a channel pair for 1oo1 evaluation
If you want to use only one channel of a channel pair (for 1oo1 evaluation), connect the
unused channel to a resistance. Select the resistance to achieve a current between 4 and
20 mA.
9.3.16 HART basics
9.3.16.1 What is HART?
The HART function enables you to also operate the analog modules with digital
communication options. The HART protocol has emerged as the de facto standard protocol
for communication with intelligent field devices: HART is a registered trademark of the
"HART Communication Foundation" (HCF), who owns all rights for the HART protocol.
Note
The SM 336; F-AI 6 x 0/4 ... 20 mA HART module supports the HART protocol version 5 to
6.
9.3.16.2 Properties of HART
What are the advantages of HART?
The use of HART analog modules offers the following advantages:
● Connection-compatible to analog modules: current loop 4 to 20 mA
● Additional digital communication via the HART protocol
● HART requires less power, important for use in hazardous areas
● Numerous field devices with HART functions currently in use
What are typical HART applications?
● Commissioning of field devices (central parameter assignment)
● Field device parameters can be changed online
● Information, maintenance and diagnostic displays for field devices
WARNING
The HART protocol is not safety-oriented!