Front Panel; Rear Panel - Honeywell MT13-520 Manual

2.3

2.3 FRONT PANEL

Controls on the front panel of the power supply consist of a switch, a
POWER RESET
button, a and a margin jumper. The function and operation of
FAN CONTROL, LO-NOM-HI
the power and reset controls are discussed elsewhere in this manual. The margin jumper is
a power supply test/maintenance diagnostic aide and should be left in the (center)
NOM
jumper position at all times. The EC power supply contains a fan control switch/jumper
and is set for either a thermally-controlled or fixed-fan power (see Figure 3-2). One setting
varies the fan voltage with temperature and load. The other setting provides a continuous
27 volts.
The front panel contains indicators that provide status of the unit's performance and aid in
fault isolation. The LED indicators on the bottom left of the front panel (the power supply)
give an indication of the power-supply status. Another indicator on the fan assembly
lights if the fan assembly fails. LEDs on each of the boards are used in conjunction with an
alphanumeric display on the processor board to isolate malfunctions on the boards. Further
information on the use of the module indicators is located in Section 3 of this manual.

2.4 REAR PANEL

The rear panel contains the I/O boards (paddleboards), chassis power-cable, a 100-pin
backplane breakout board (if provided), and a grounding lug. As shown in Table 2-1 the
I/O boards are installed in the chassis in the slot corresponding in number to the applicable
board installed in the front of the module. All communication with the Micro TDC 3000 is
through the I/O boards.
There are two methods of communicating between nodes on the system. The conventional
LCNI I/O paddleboards form the Local Control Network with coaxial cables that run to all
of the LCN nodes in a network. In the network, all LCN I/O boards are connected by T
connectors and cable (or to a terminating load on the last T in a series). Because of loading
characteristics, the minimum LCN cable length is 2 meters (6 feet), so there may appear to
be some cable "waste" when nearby LCN boards are interconnected. In all LCN cabling,
the I/O board connectors are marked A and B; make sure that the A cable connects to the A
connector and that the B cable is connected to the B connector.
A special short distance LCN network has been designed which uses twisted pair and
multinode module backplane wiring instead of coaxial cable and T connectors. The I/O
paddleboards used for this network are the TP485 boards. This twisted pair LCN cabling
follows the RS 485 interface standard. One of the K2LCN processor boards and TP485
I/O cards in slot 9 of each tower supplies clock to other nodes on the short distance
network. The twisted pair cables which tie this short distance LCN together are keyed so
that cables A and B cannot be misconnected and terminating loads are built-in.
Ribbon cables are used to connect to such items as the Winchester Drive, Cartridge Drive,
and other peripherals. Other connectors, for example RS 232C or RS 449 on the
Computer Gateway, are also used.
Multinode Module Service 2-9 9/95