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

Chapter 7: Enabling and Using HART on the 1769sc-OF4IH
User’s Manual 0300217-03 Rev. A
7-35
The command status, the second byte in the reply packet for the module specific
command, can return three different responses, SUCCESS, RUNNING and DEAD.
These responses echo the state of the module at the time the command is sent. The
conditions for each response are as follows:
SUCCESS will be sent back under the following conditions:
 Command and HART Channel number are both valid.
 HART channel is enabled.
 Command handle matches currently active handle and the handle is in the
HOLD state.
 After replying with a SUCCESS, the handle will become inactive, thus allowing
for next pass-through or host initiated update of device information.
RUNNING will be sent back under the following conditions:
 Command and HART Channel number are both valid.
 HART channel is enabled.
 Command handle matches currently active handle.
 HART channel is already in the state of handling a pass-through command.
Reply will be sent back without additional events triggered.
DEAD will be sent back if any of the following conditions are 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. Examples are:
invalid handle, handle timed out, channel under device information gathering,
and etc.
The following ladder demonstrates how to perform the pass-through request and query
process.
Figure 7-10a (Pass-Through Ladder)