Rockwell Automation 1770-HT8 SMART TRANSMITTER - Manual (Page 85)

Communicating with the Smart
Transmitter Interface
Chapter 4
Communicating with the Smart Transmitter
Interface
4-20
No Operation (hexadecimal command 00)
The Smart Transmitter Interface performs “no operation” when it receives
this command. Use it to simplify your programmable controller ladder
logic by issuing BTWs and BTRs in pairs, and using this command when
no specific information is required from the Smart Transmitter Interface.
When the programmable controller requests a BTR response after the
BTW sending hexadecimal command 00, the Smart Transmitter Interface
responds with “No Error”.
Enable Poll and Response Mode (hexadecimal command 01)
This command puts the Smart Transmitter Interface into Poll and Response
mode. Data from any bursting HART field devices is ignored in this mode.
Enable Burst Monitor Mode (hexadecimal command 02)
This command puts the Smart Transmitter Interface into Burst Monitor
mode. In this mode the Smart Transmitter Interface monitors the channels
specified in the Smart Transmitter Interface Data field, for bursting data.
For example, if hexadecimal channels 05, 07 and 1E are to be monitored,
then the Smart Transmitter Interface Data field should contain the four
bytes: “05 07 1E FF”. The channel list must be terminated with
hexadecimal FF. You must still set each of the HART field devices into
burst mode before any Burst Data packets can be received by the Smart
Transmitter Interface.
When the Smart Transmitter Interface is monitoring the bursting field
devices in a “round-robin” fashion, the received data is placed into the
Burst Data table. You can access this data by sending a Read Burst Data
command (hexadecimal 11) to the Smart Transmitter Interface.
Send Message to Device (hexadecimal command 10)
Use this command to send a HART poll to a field device on the specified
channel. The HART poll is placed in the Smart Transmitter Interface Data
field. The Smart Transmitter Interface returns field device responses as
data in a BTR or DF1 Response. The field device response is passed on as
is except for the leading preambles, which are removed.