RMG EC 900 Operating Instructions Manual page 16

CONSTRUCTION AND FUNCTION
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Type EC 922
Modem
8
Power pack
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Pressure transmitter
Emergency battery (corrector)
Internal communication module
optionally with modem or Ethernet interface
Aerial
RS 232 / RS 422 / RS 485
interface
Ex zone 2
Safe area
24 VDC or
115/230 VAC
The EC 922 version is intended for use in
Ex zone 2; it is not permissible to operate this
device in Ex zone 1. It is externally powered
and includes a power pack (24 VDC or
115/230 VAC). A lithium cell serves as an
emergency battery to supply the volume cor-
rector. However, it does not supply the inter-
nal communication module.
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.
Note: The wiring compartment has been re-
worked in the meantime. You can see the cur-
rent version on page 28.