Siemens SITRANS F M TRANSMAG 2, Руководство по эксплуатации, Страница: 99 / 114

Profibus Communication
B.6 Diagnostics
SITRANS F M TRANSMAG 2
Operating Instructions, 11/2009, A5E00102775-07
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0 for safety. This value represents the "SET_TOT" parameter of the "Totalizer Function
Block" defined in the PROFIBUS-PA profile.
Table B- 7 Totalizer mode of the parameter "SET_TOT"
Bit
1 Bit
0 Profile disignation Meaning
0 0 totalize totalizer running
0 1 reset totalizer stopped and reset to 0
1 0 preset not implemented; command not accepted
The transferred value is effective until being changed. For example, the totalizer stays at
value 0 after sending the value 1 (reset totalizer) until the "SET_TOT" parameter is changed
again.
Every value of the "SET_TOT" parameters affects the corresponding totalizer independently
of the others. The cumulating of measured values also takes place independently, i.e. the
totalizer reading net must not correspond to the total of totalizer reading forwards and
totalizer reading reverse, especially when a totalizer has been reset.
Note
Resetting and starting of the totalizers can also be triggered parallel to cyclic communication
by an acyclic command. This should be avoided at all costs because the behavior of these
totalizers is then dependent on the exact chronological order of these commands.
B.6 Diagnostics
The diagnostic data can be requested with the "Slave_Diag" service.
If extended diagnostic messages (Ext_Diag_Data) exist, this is displayed by the "Diag_Flag"
of the "Data_Exchange" service. If the master then calls the "Slave_Diag" service, the
external diagnostic data are supplied in the following form by the device:
Table B- 8 Format of diagnostic data
Byte
No. Profile designation Value Meaning
1 Header 8 (dec.) (fixed) length of diagnostic data (number of
bytes)
2 254 (dec.) (fixed)
3 1 (fixed)
4 0 or 1 Display of changes in diagnostic data (see
below)
5 Byte 1 (s. below) Diagnostic information
6 Byte 2 -- (not supported)
7 Byte 3 -- (reserved)
8
Diagnosis
Byte 4 (s. below) Note on additional diagnostic data
The total length of the external diagnostic data is always 8 including the header.