Spectrum Controls 1756sc-OF8H Series A - Manual (Page 84)

70 ControlLogix ™ Analog HART Modules
Figure 7.3 (Primary, Secondary and Slave connection)
!
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the IF8H or the OF8H. the IF8H or the OF8H. the IF8H or the OF8H. the IF8H or the OF8H. the IF8H or the OF8H.
HART modules communicate using two different messaging schemes
connected and unconnected. Connected messages are messages that are
periodically updated and maintained by the ControlLogix processor. The
frequencies of the updates are adjustable and are defined by the user.
Connected messages include data contained in the module’s input image,
and in the case of the OF8H module, the output image. Unconnected
messages are messages that are transmitted over the control network and
are performed asynchronously from the normal processor scan.
Unconnected messages include data contained in the module’s
configuration image (i.e. Local:e:C), and CIP messages such as the
module specific commands. Module specific commands include the
HART pass-through commands, HART suspension and resume, and the
get HART device information command.