Rockwell Automation 1770-HT8 SMART TRANSMITTER - Manual (Page 76)

Chapter 4
C Communicating with the Smart
Transmitter Interface
4-11
Figure 4.7
HART Response of Burst Data Packets Ć HART Field Device to Smart Transmitter
Interface (Long Frame Format)
90072
Command
Long Frame HART Address
HART Delimiter
Preamble
Byte Count
Response Code
Data
Check Byte
Higher Order
Slave Address Bits
Device Burst Mode Bit
0 Disabled
1 Enabled
Master Address Bit
0 Secondary Master
1 Primary Master
Frame Type
001 Burst Frame
110 ACK Frame
Reserved
Long/Short Frame Bit
0 Short
1 Long
1 0 0 0 0
HART
HART Command
This one-byte field echoes the HART command being responded to. This is
either the last command sent to the device, or the HART command for
which burst data is being transmitted by the device. Program the host
processor to verify that this field contains the correct command before it
processes the remaining data in the packet.
Byte Count
This one-byte field indicates the number of bytes to follow this field
excluding the check byte. Valid values are 2 to 113. It indicates to the host
processor the size of the received data field.