Spectrum Controls 1756sc-OF8H Series A - Manual (Page 96)

82 ControlLogix ™ Analog HART Modules
• Command and HART Channel number are both valid.
• HART channel is enabled and communication has been established,
meaning at least the device addressing information is available.
• HART channel is already in the state of gathering device information.
Reply will be sent back without additional events triggered.
DEAD will be sent back if any of the following conditions is true:
• Command or HART Channel number is invalid
• HART channel is not enabled
• HART communication has not been established, meaning that the 5-
byte unique address has not been determined yet.
• All other conditioned not generating RUNNING or SUCCESS.
The following figure demonstrates how a module specific command can
be sent to the module using ladder logic.
Figure 7.9 (Sending a Module Specific Command Using Ladder)
HART Channel Suspension and Resume
Sometimes referred to as "Out of Service" and "In Service" respectively,
these commands can be utilized to suspend or resume operation of an
enabled HART channel. When a HART Suspend Channel command is
sent, the HART module will keep the current HART configuration
information and stop all communication processes on the selected channel.
However, there will be overriding conditions such as configuration change
affecting the overall module operation, which will cause the HART
function to reset based on the new configuration. Normal HART
operation will resume if the HART Resume command is sent to the
module during a HART Suspension.