sepam 20 user manual - Schneider Electric

Modbus communication Access to remote settings
PCRED301005EN - 06/2008
CAUTION
RISK OF UNINTENDED OPERATION
b The device must only be configured and set by
qualified personnel, using the results of the
installation protection system study.
b During commissioning of the installation and
following any modification, check that the Sepam
configuration and protection function settings are
consistent with the results of this study.
Failure to follow these instructions can result
in equipment damage.
Remote setting
Data that can be remotely set
Writing of the settings of all the protection functions may be accessed remotely.
Exchange principle
Remote setting is allowed for Sepam units.
Remote setting is carried out for a given function, relay by relay.
It takes place in two steps:
b first of all, the master indicates the function code and relay number, followed by the
values of all the settings in the a "write request frame". The request is acknowledged
to free the network
b the master then reads a reply zone to find the required information by means of a
"reply frame", a reply zone designed for checking that the settings have been
processed. Each function has its own particular reply zone contents. The contents
are same as those of the reply frame.
To use remote setting, it is necessary to make all the settings for the function
concerned, even if some of them have not changed.
Request frame
The request is made by the master using a "write n words" (function 16) operation at
the address 2100h. The zone to be written contains a maximum of 125 words.
It contains the values of all the settings. It consists of the following:
2100h
B15 B14 B13 B12 B11 B10 B09 B08 B07 B06 B05 B04 B03 B02 B01 B00
Function code Relay number
Settings
..............
(special field for each function)
..............
The content of the address 2100h may be read using a "read n words" (function 3).
The function code field may have the following values:
b 01h to 99h (BCD encoding) for the list of protection functions F01 to F99.
The relay number field is used as follows:
b for protection, it indicates the relay involved, varying from 1 to N, N being the
maximum number of relays available in the Sepam. It may never be equal to 0.
Exception reply
In addition to the usual cases, Sepam can send type 07 exception replies
(not acknowledged) if:
b another remote reading or setting request is being processed
b the remote setting function is inhibited.
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