Spectrum Controls 1769sc-HART Modules - Manual (Page 101)

Chapter 7: Enabling and Using HART on the 1769sc-IF4IH0
User's Manual 0300215-03 Rev. A
7-33
•
HART channel device information is available.
RUNNING will be sent back when all of the following conditions are met:
•
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.
7.4.2 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
suspend HART command is sent, the HART module will keep the current HART
configuration information and stop all communication processes on the selected channel.
However, there are overriding conditions such as a configuration change which can cause
the HART function to reset. Normal HART operation will resume if the resume HART
command is sent to the module during a HART suspension.
Note: The HART suspend and resume can be initiated by setting a bit in the output
image. Refer to Chapter 6 for more details.
Note: If the resume command is received, without previously receiving a suspension
command, it will be ignored.
Note: The selected channel will resume normal HART operations three minutes after
the suspension command has been received by the module. Pass-through for that
channel resets the timer to 3 minutes.
Table 7-12 (HART Suspend/Resume)
HART Channel Suspend/Resume command request – command message packet structure
Field Value Definition
HART Channel
Number 0x00 – 0x03 (1 byte)
0xFF (-1) Apply to all 8 channels Enabled HART
channel number
Command Number (1 byte)
0x05: Suspend (Set service mode)
0x06: Resume (Reset service mode) The command
number to suspend
or resume