Diagnosis Messages Of The Fb Modbuspn - Siemens SIMATIC S7 Manual

7.3

Diagnosis Messages of the FB MODBUSPN

Messages at the
STATUS Outputs
of the FB
Error Messages of
the called SFCs
and FBs
Error messages of FB MODBUSPN at the output STATUS_MODBUS
STATUS Event text
(Hex)
A001 The parameter data block MODBUS_PARAM is too
short.
A002 The parameter end_x is less than start_x.
A003
The DB to which MODBUS addresses shall be mapped
is too short.
Minimum length:
- register values (end_x - start_x + 1) * 2
- bit values (end_x - start_x + 7) / 8
Other possible reasons:
•
Wrong initialization parameter (S7 is client)
•
Wrong address area in the request telegram of
the client (S7 is server)
A004 Applies only if S7 is client:
An invalid combination of DATA_TYPE and
WRITE_READ is given.
MODBUS / TCP communication via the integrated PN interface of the CPU
2XV9450-1MB02; Manual edition 2.1
The block MOBUSPN has 3 status outputs: STATUS_MODBUS,
STATUS_CONN and STATUS_FUNC.
STATUS_MODBUS displays the error numbers regarding the processing of
Modbus telegrams, whereas STATUS_CONN displays the error numbers
regarding the connection handling. STATUS_FUNC shows the name of the
function, which caused the error. STATUS is valid when ERROR is TRUE.
Below you can find a list of FB-specific error messages.
The FBs MODBUSPN, MOD_CLI and MOD_SERV use the standard
functions SFC6, SFC20, SFC24, SFC51 und SFC52. The error messages of
these blocks are passed on to STATUS_MODBUS without any changes.
The block TCP_COMM, called by MOD_CLI or MOD_SERV, uses the
standard blocks SFB4, FB63, FB64, FB65 and FB66. The error messages of
these blocks are passed on to STATUS_CONN without any changes.
For further details on the error messages, please consult the diagnosis buffer
or the online help of the SIMATIC Manager.
Remedy
Correct the length of
MODBUS_PARAM
Correct the parameterization in
DB MODBUS_PARAM
Extend the DB.
S7 is Client: Correct the
parameters START_ADDRESS
or LENGTH
S7 is Server:
Modify the request of the client.
Correct the parameters. Only
data type 1 or 3 can be written.
Diagnosis
7-6