II - DCE FEL ČVUT v Praze

SIMATIC S7 HART Analog Modules
Structure of the
response data
record
Evaluating the
response data
4-32
The following figure shows the structure of the response data record, which
contains the response to the HART command you sent previously and any
error or status bits.
Byte 0
Byte 1
Byte 2
Byte 3
to
6
Byte 7
Byte 8
Byte 9
Byte 10
Byte 11
to
Byte 239
7 6 5 4 3 2 1 0
always 0 (”monodrop”)
Processing state
1=module command,
0=HART command
7 6 5 4 3 2 1 0
0
see Table 4-13
7 6 5 4 3 2 1 0
see Table 4-14
.
.
.
.
.
0 = idle
1 = waiting
2 = waiting in burst mode
3 = executing
4 = success; no data
5 = success; with data
6 = success; burst data
7 = error
HART group error bits
HART protocol error during
response from field device to
module
always 0, reserved for time stamp
From here onwards: HART
response with status
Last command
Number of bytes for response
1. HART status byte and
2. HART status byte, see HART
technical specification
Fig. 4-15 Response data record of the HART analog module
Response data
according to HART:
Length: No. of bytes - 2:
max. 228 bytes
When you have an up-to-date response data record, you can check the
following:
You can use the “last command” byte to check that the response belongs
to the command sent.
You can evaluate the “Group error bits” (see Table 4-13) to locate
individual errors.
You can obtain more information from “HART protocol errors during
response” (see Table 4-14) and both HART status bytes.
that in the group error bytes the corresponding bits will be set to “1”.
I/O Modules with Intrinsically-Safe Signals
C79000-G7076-C152-04