Fc81: Read The Response With Sfb 52 To Db81; Db80: Compact Message Format; Db80: Transparent Message Format - Siemens SIMATIC ET 200SP HA Equipment Manual

Table B-1
Byte
0
1
2
3
4
5
6
7
8
9
10
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
Byte
0
1
2
3
You can learn when the response from the field 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
m3: CALL SFB52, DB52
AI 4xI 2-/4-wire HART ISOL HA
Equipment Manual, 07/2022, A5E50101523-AB

DB80: Transparent message format

Initial value (hex)
00
05
82
98
CF
38
84
F0
01
00
98

DB80: Compact message format

Initial value (hex)
20
05
01
00

FC81: Read the response with SFB 52 to DB81

REQ :=M1
ID :=DW#16#200
INDEX :=81
MLEN :=200
B.2 HART job and response data records
Comment (Hex)
Req_Control
(00 = Transparent message format.
40 = Transparent message format with SHC sequence)
Number of preamble bytes (05-14)
Start character
(02 = Short Frame with command 0)
(82 = Long Frame with other commands)
Address
(with command 0, the address is exactly 1 byte long and has
the value 0.)
Command (CMD)
Length in bytes
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.)
Comment (Hex)
Req_Control
(20 = Compact message format
60 = Compact message format with SHC string)
Number of preamble bytes (5...20, 255)
Command (CMD)
Length in bytes
Explanation
Read request
Module address
Data record number 81
Target length
HART operating data records
79