F 8627X (0650)
379
6.4.3 Connection via port 502
Via F 8627X port 502, the F 865x central module operates as a MODBUS TCP slave and can
be directly reached.
The BUSCOM Variables can be accessed via the BUSCOM adresses configured in ELOP II.
The MODBUS slave on the central module provides the MODBUS function codes, as de-
scribed in the manual "Functions of the operating system" HI 800 105.
The F 8627x and F 865x react to a MODBUS request via port 502 as follows:
• If the F 8627X is in mono operation mode (i.e. no HSR connection to a second
F 8627X), then the F 8627X must have a connection to the F 865x, which in turn
must be in RUN status to answer a MODBUS request with the corresponding MOD-
BUS response.
• If two F 8627X are operating redundantly (i.e. HSR connection to a second
F 8627X), then one of the two redundant F 8627X must have a connection to its
associated F 865x, which in turn must be in RUN or MONO status to answer a
MODBUS request with the corresponding MODBUS response.
If the MODBUS request cannot be passed on to an F 865x, the F 8627X sends the error code
0x0B back to the MODBUS master.
Using port 502, if the recommended polling interval "t
Poll
" is ignored, the MODBUS communi-
cation may behave as follows:
• Should the same master send other MODBUS request within 50 ms, other MOD-
BUS requests from the same master are received within 50 ms after a MODBUS
request, the F 8627X transfers last MODBUS-Request from this master to the
F 865x central module, if:
• the central module is not processing a MODBUS request from this master and
• 50 ms are expired.
• As long as the F 865x is processing a MODUBUS request from a master, it will only
accept another MODBUS request from this master after a minimum of 400 ms.
• In case of a new connection, the first request is passed on to the F 865x after
≥ 50
ms.
Note The events query and the synchronization of the central module (CM)
software clock is only possible via TCP server port 502.
The HSR communication for a MODBUS TCP slave via port 502 is
independent of the HIPRO-S-DIRECT mode.
Note Processing each MODBUS Request increases the cycle time for the
F 865x central module. To avoid increasing the cycle time too much,
the F 8627X limits the minimal polling interval per MODBUS master to
50 ms.
Note If the MODBUS master is only connected to one F 8627X on the
H41q/H51q, the MODBUS master must
always be connected to the
F 8627X plugged into the left F 865x via an Ethernet cable.
This ensures that the data written most recently from the MODBUS
master are also reflected in the data currently being processed by the
user program.
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