THE CMX-24I BOARD
E1110A.DOC
Data and design subject to change without notice. Supply subject to availability
© Copyright by CERBERUS AG, CH-8708 Männedorf, Switzerland 1995
01.96
15[51]
The switches SW1-1, SW1-2 and SW1-3 are used to define the board type. For the CMX-24I they must have the
setting shown in Table 4.1.
SW1-1
ON
SW1-2
ON
SW1-3
ON
Table 4.1 - Board type
The switches SW2-1, SW2-2 and SW2-3 are used to define the meaning that the CMX firmware assign to the input
status. The meaning is assigned to the inputs in groups of eight, and so 3 switches are enough to define the meaning
of 24 inputs. If the switch is set OFF, the eight inputs corresponding to it are evaluated active when they are closed
(this condition is stated as "normally open" in Table A.2 in Annex A). If the switch is set ON, the inputs are
complemented, i.e. their active status corresponds to the open state (this condition is stated as "normally closed" in
Table A.2 in Annex A).
In the upper left part of board there are two double jumpers, marked JP1 and JP3. Each one has a "A" jumper and a
"B" jumper. Their setting is as follows and
must not be changed
:
JP1
JP3
A
OFF
ON
B
ON
OFF
Table 4.2 - JP1 and JP3 settings
The I/O board (CD 91200) of the CMX-24I is able to accept up to 24 inputs. On the board it is easy to recognize the two
rows of twelve photocouplers each, the small blocks with four pins, the two LEDS blocks of 24 and 4 LEDs
respectively, on the left board side and the DIN 64-pins connector on the right side.
The 24 LEDs are linked to the I/O port. When a LED is ON this means that the input is closed at the corresponding
input port. Note that the LED signifies only a physical condition (i.e. current flowing through the diode), while the logical
meaning of the input is assigned by the switch setting (see Table A.2).
Looking frontally to the LEDs rows, the four lower LEDs have the following meaning (Fig. 4.1):
−
the upper left is the RS-485 line
TX monitor
: during normal operation it blinks according to the signals
transmitted.
−
the upper right is the RS-485 line
RX monitor
: during normal operation it blinks according to the signals
received.
−
the lower left is the
power supply monitor
: it must be steady ON when the CMX is properly powered.
−
the lower right is the low
voltage monitor
: during normal operation it is OFF. It lights on when the power
supply voltage drops below the lower limit of 11.4 V.
The board layout is common with the other CMX models (CMX-24O and CMX-16/8). The CMX-24I however lacks the
three IC marked on the PCB as U1, U2 and U3, as well as the related jumpers marked W25, W26 and W27.
The only feature that can require a maintenance intervention is the fuse on the I/O board. The fuse is soldered to the
board and it is intended for board protection and
not for field protection
. If the fuse blows out, probably there is
something wrong with the board. Send it back to Cerberus Dati for maintenance.
