SMAR HI302, User Manual, Page: 27 / 92

HI302 - User’s Manual
3.7
IMPORTANT
If the command 0 is selected in the HIRT.ID_CMD parameter, the HI302 will find the
device by varying the polling address from 0 to 15. This is a useful function if the user
does not know the device’s polling address because it identifies the device
automatically.
♦
POLL_CMD : Specify the command that will be used to scan the device after its
identification and the first variable reading for the HIRT block. The user can choose
the command 1, command 2, command 9 (available for version-6 HART) or command
33 (standard). See a detailed explanation about the HIRT block in the Appendix, to
identify which parameter is related to the commands.
♦
POLL_CTRL : Indicates if the HI302 will keep on polling the device using the
command selected in HIRT.POLL_CMD, after the identification and initial filling of the
HIRT block.
IMPORTANT
The HI302 will poll the device only if the block performed the initial procedure
successfully and reached the UPDATE status. See the BLK_EXEC_STATE parameter.
♦
COMMON_CMD_CTRL : This parameter is a 10-filter set that prevents a HART
command configured and not supported by the device, to be sent. Their elements
should be filled in the HCD block with the definition index of the HART command. See
the chapter “Example of Configuration” for more details.
Configuring the HVT Block
The HVT block can be seen as a complement for the HIRT block. It includes all non-
mapped variables in the HIRT block. Thus, it is not necessary to have all the parameters
configured, except the following:
♦
MODE_BLK : Should be set on AUTO . If it is set on OS, the block operation will stop.
When the block is set on OS, it returns to the initial Identification state. When the block
is set on AUTO, the block identification and the update process is repeated if there is a
valid TAG in the DEV_TAG_SEL parameter.
♦
DEV_TAG_SEL : This parameter doesn’t need to be configured initially. It connects the
HIRT block to the HVT block temporarily. As a result, it allows the HVT block to
communicate with the HART device. This connection is done through the HART_TAG
parameter. If the supervisory software has to read the HVT parameters for any device,
it should fill the device HART_TAG. The HVT block searches the HIRT blocks for a
written HART_TAG in order to make an association with it. See the chapter about
Functioning Theory for more details.
HI302-I - Configuring the MAI Block
All HI302-I inputs have an input circuit for the 4-20 mA acquisition. So, it is possible to
instantiate a block with a multiple analog input or
with 8-output parameters that provide
the percentage value of the analog input related to the 16 mA range (4 mA = 0% and 20
mA = 100%). This block doesn’t need any configuration to operate.
•
MODE_BLK : Set on AUTO.
•
CHANNEL : Standard value equal to 0.
See the Function Block manual for more details on configurations and options.