Table B-1 DB80: Transparent message format
Byte Initial value (hex) Comment (Hex)
0 00 Req_Control
(00 = Transparent message format.
40 = Transparent message format with SHC sequence)
1 05 Number of preamble bytes (05-14)
2 82 Start character
(02 = Short Frame with command 0)
(82 = Long Frame with other commands)
3 98 Address
(with command 0, the address is exactly 1 byte long and has
the value 0.)
4 CF
5 38
6 84
7 F0
8 01 Command (CMD)
9 00 Length in bytes
10 98 Checksum (CHK)
(calculated as EXOR addition starting from byte 2 "Start
character" up to the last byte of the command) The check‐
sum must not be sent with the job.)
A HART command can also be sent in compact message format. In this case, the data transmitted
via DB 80 is reduced to 4 bytes.
Table B-2 DB80: Compact message format
Byte Initial value (hex) Comment (Hex)
0 20 Req_Control
(20 = Compact message format
60 = Compact message format with SHC string)
1 05 Number of preamble bytes (5…20, 255)
2 01 Command (CMD)
3 00 Length in bytes
You can learn when the response from the eld device was received by cyclically reading data
record DS81 for HART channel 0. The response is always supplied in transparent message format.
Table B-3 FC81: Read the response with SFB 52 to DB81
Explanation
m3: CALL SFB52, DB52
REQ :=M1 Read request
ID :=DW#16#200
INDEX :=81
Module address
Data record number 81
MLEN :=200 Target length
HART operating data records
B.2 HART job and response data records
AI 4xI 2-/4-wire HART ISOL HA
Equipment Manual, 07/2022, A5E50101523-AB 79
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