RMG EC 900 Operating Instructions Manual page 15

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Type EC 921
Modem
Battery (modem)
12-20 VDC
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Pressure transmitter
Battery (corrector)
Internal communication module
optionally with modem
Aerial
RS 232 / RS 422 / RS 485
interface
Ex zone 2
Safe area
ISS Batt
battery module
(Option)
CONSTRUCTION AND FUNCTION
< No longer available >
The EC 921 version is intended for use in
Ex zone 2; it is not permissible to operate this
device in Ex zone 1. It is powered by two lithi-
um batteries as standard: one for the correc-
tor and the other for the internal communica-
tion module.
Note: The wiring compartment has been re-
worked in the meantime. You can see the cur-
rent version on page 28.
The device has an optical interface and an
electrical interface. The electrical interface
can be configured as an RS 232, RS 422 or
RS 485 interface using jumpers in the casing.
RS 485 is the default configuration (see also
page 32).
Apart from the fact that the external CU 900
communication module can also be fitted with
current outputs, the internal and external
modules have the same range of functions. So
the communication module can be fitted with
a fixed-line or radio modem. Alternatively, the
"modem" socket provides another interface,
e.g. TCP/IP or USB.
Power can optionally be supplied by an exter-
nal ISS Batt battery module. With this module,
it is also possible to operate a GSM modem.
This module is used for power supply only and
has no interface.
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