Service manual

Relay Control Unit Cards
Processor (SCS802–079)
CARD DESCRIPTION
The Relay Control Unit Processor is a T2 transputer based card controlling the five lower 37
way D-types, with 64 relay loops and sixteen opto-isolator loops as detailed below.
The relay loops are specified as follows :-
Max voltage across relay - 100V dc
Max current through relay - 0.5A dc
Max power switched by relay - 10W
Contact resistance - 150 mom
Life at full load - 5 million operations
Typical operation time - 0.4 msec
There are also sixteen opto-isolators taken out as current loops to a separate 37 way D-type.
The current loop is specified as follows :-
Absolute maximum current through loop - 60mA
Max reverse voltage across loop - 6V
Surge current - 1.5A
Minimum current to operate loop - 2mA
The four upper 37 way D-types on the back panel are for expansion and customization of
the box and will be covered on separate options sheets.
LED INTERPRETATION
1(red) On indicates transputer error
2(green) On indicates link 0 active
3(green) On indicates link 1 active
4(green) On indicates link 2 active
5(green) On indicates link 3 active
6(red) On indicates Reset active
7, 8, 9, 10, 11, 12 and 13 (yellow) Software controlled. Off indicates
normal operation
Digital Service Manual
Issue 3 Page 41
SCS802-079
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