SMAR HI302, User Manual

Page: 45 / 92

HI302 - User’s Manual
5.11
delimiter and so on. Only the RESOURCE and the HCFG blocks are necessary to operate
the BAYPASS mode. Any HIRT or HVT block instantiated will stay on BYPASS status
(BLK_EXEC_STATE parameter).
IMPORTANT
To use the BYPASS mode, the user should write BYPASS on the
HCFG.COMM_BEHAVIOR parameter.
The HCFG.BYPASS_STATUS indicates the situation of the message and may assume
the following values:
•
IDLE , the channel may send a message using the BYPASS_REQ_N parameter or
there is a message available to be read through the BYPASS_RES_N parameter.
Even though, the channel is monitoring another master’s communication or a device
in burst mode, it will be available to send a message.
•
BUSY , the applicative ordered a REQUEST that is being executing,
•
TIMEOUT , after a predefined number of repetitions, it was not possible to receive a
valid message for the request.
The HI302 does not perform any integrity or content checkup on the message received. It
transmits what it has received to the communication channel. The applicative must ensure
the quality of the messages and the response interpretation.
Sequence for Sending a HART message through a BYPASS
•
Check if the HCFG.BYPASS_STATUS[N] parameter is on IDLE or TIMEOUT. If positive,
the message can be written on the HCFG.BYPASS_REQ_N parameter. The HI302 will
check if the channel is available and transmit the content of the
HCFG.BYPASS_REQ_N parameter.
•
While the HCFG.BYPASS_STATUS[N] parameter is on BUSY, the HI302 is waiting the
response or repeating the request up to the limit programmed in the HCFG.RETRIES[N].
•
The HCFG.BYPASS_STATUS [N] parameter goes to IDLE if it has received a valid
message. It goes to TIMEOUT, in case it hasn’t received a valid response yet.
IMPORTANT
As the message has to be entirely supplied by the applicative
writing on the HCFG.BYPASS_REQ_N, the applicative will
guarantee that the message is in the right format, with the right
address, etc.