13
2.2.6
Installing Additional Option Modules
Isolate ALL sources of power before installing or removing printed circuit boards.
ATTENTION
OBSERVE PRECAUTIONS
FOR HANDLING
ELECTROSTATIC
SENSITIVE DEVICES
Observe anti-static precautions at all times when handling printed circuit
boards.
2.2.6.1 Additional Signalling Line Circuits
To extend the number of signalling line circuits /
loops or to replace an existing loop driver card
(Lxp-901) follow the procedure described below.
An example of the loop driver is shown opposite.
This is provided with a plastic grip handle on the
top edge to ease removal of the card from the
Base Card.
Open the enclosure and then open the display
plate (it is hinged on the right hand side and there
is a magnetic catch strip on the left-hand side) to
gain access to the Base Card.
A section of the Base Card identifying the
locations for each loop driver is shown in the
picture opposite.
Loop Driver
– Component Side View
To install a loop driver, remove the retaining strap,
then gently guide the loop driver printed circuit
card into the guide slots of the machined end
blocks and then push into place onto the
connector on the Base Card.
Ensure that the pins of the connectors are
correctly aligned. The loop driver should be
inserted with the component side of the board
placed on the left-hand side. Replace the retaining
strap.
The Base Card can accept up to four signalling
line driver cards
– it does not matter which
positions are used. Ensure that the signalling line
wiring is made to the terminal block positions
appropriate to the line driver cards actually
installed.
Close the chassis display plate and then close up
the enclosure.
Component side of
Loop Driver Card
Machined End
Block
LOOPS
1
2
3
4
2.2.6.2 Removing a Loop Driver Card
To remove a loop driver, remove all power and follow the procedure above but:
Take a firm hold of the lever located on top of the loop driver card. Gradually and carefully pull the loop
driver vertically away from the base card and guide it out of the slots in the machined end blocks.
Replace with the replacement card as described above.
