UTMC OTU/MOVA Handbook
667/HB/31601/000
Page 20
Issue 5
be operated in the inverted position (i.e. with the terminals pointing downwards). See
section 4.4.1 on page 28.
A Lithium coin cell battery is provided on the Processor card and supports the Real
Time Clock during power failures for at least 7 months. This battery is plug-able to allow
easy replacement.
The Processor card also has a ‘Gold Cap’ capacitor fitted that allows the Lithium coin
cell battery to be changed without loss of power to the Real Time Clock. The Gold Cap
device provides a minimum of 30 minutes support.
The two batteries have the following specifications:
Battery
Type
Support
Unit Battery
12V Lead Acid
20 minutes (Typical)
RAM Battery
Lithium
418/4/53433/000
At least 7 months after the main
support battery has expired.
3.3 MECHANICAL
The construction of the unit is based on the standard 3U high, IEC297 Eurocard rack
system. The unit does not use the conventional backplane approach. Instead it uses an
expansion bus (see section 2.10 on page 18), to interconnect the cards electrically. The
rack does not need to have guide rails, but if present they need to be on 25.8mm
spacing. Mechanically the cards are held in a stack, by four sets of pillars and fixings,
and held in place on a mounting plate (see Figure 2.2 on page 11). The mounting plate
also accommodates the modem and PSU assemblies, and is used to fix the total unit
assemblies to the 3U rack, or enclosure mounting side angle bracket.
DIMENSION
MINIMUM
MAXIMUM
Height
130mm
130mm
Width
115mm for semi-integral
unit with PSU and CPU
192mm for freestanding unit with
PSU, CPU and 3 I/O cards
Depth
255mm, excl. cables
300mm, incl. rear cables
3.4 ENVIRONMENTAL
Temperature
-15°C to +60°C ambient
Humidity
20% to 95% non condensing at 40°C