Spectrum Controls 1756sc-OF8H Series A - Manual (Page 157)

Ad Ad Ad Ad Additional HAR ditional HAR ditional HAR ditional HAR ditional HART Pr T Pr T Pr T Pr T Protocol Inf otocol Inf otocol Inf otocol Inf otocol Infor or or or orma ma ma ma mation tion tion tion tion
This chapter discussed the HART protocol and provides references for
additional information about the protocol. This chapter provides:
• HART Protocol background information.
• Common Practice command sets.
• Extended command sets.
• References to additional information.
Ov Ov Ov Ov Over er er er er vie vie vie vie view w w w w HART Field Communications Protocol is widely accepted in the industry
as the standard for digitally enhanced 4-20mA communication with smart
field instruments. The HART Protocol message structure, command set
and status are discussed in this chapter.
The HART Command Set is organized into three groups and provides
read/write access to a wide array of information available in smart field
instruments.
Universal Commands provide access to information that is useful in
normal plant operation such as the instrument manufacturer, model, tag,
serial number, descriptor, range limits, and process variables. All HART
devices must implement Universal Commands.
Common Practice Commands provide access to functions, which can
be carried out by many devices though, not all.
Device Specific Commands provide access to functions that may be
unique to a particular device.
Appendix D