Measurement Computing CIO-DISO48 - Manual (Page 10)

CIO-DISO48 User's Guide Installing the CIO-DISO48
9
In the default configuration shown in Figure 1, addresses 9 and 8 are DOWN, and all others are UP.
Address 9 = 200 hex (512 decimal) and address 8 = 100 hex (256 decimal); when added together they equal 300
hex (768 decimal).
Disregard the numbers printed on the switch
When setting the base address, refer to the numbers printed in white on the printed circuit board.
Wait state jumper
The CIO-DISO48 board has a wait state jumper which you can set to enable an on-board wait state generator.
The factory default is wait state disabled (OFF). You will probably never need the wait state because PC
expansion slot busses are limited to 8 or 10 MHz. If you get intermittent operation, try enabling the wait state to
see if that solves the problem. The Wait State jumper is shown in Figure 2 configured for OFF.
WAIT
STATE
ON OFF
Figure 2. Wait State jumper
AC input filters
There are 48 individual, optically isolated (500V) inputs in six groups of eight each that can be read back as a
single byte. The inputs are not polarity sensitive and may be driven by either AC (50 to 1000 Hz) or DC in the
range 5V to 28V RMS. Each input has a switchable low-pass filter with a time constant of 5 ms (200 Hz).
Each group of eight inputs has an associated bank of eight filter-enable switches. The switches are labeled FL1
to FL6 . The label identifies the group of inputs controlled by the switch:
 FL1 controls inputs ISO 0 to ISO 7
 FL2 controls inputs ISO 8 to ISO 15
 FL3 controls inputs ISO 16 to ISO 23
 FL4 controls inputs ISO 24 to ISO 31
 FL5 controls inputs ISO 32 to ISO 39
 FL6 controls inputs ISO 40 to ISO 47
A typical switch used to control the filters is shown in
Figure 3. The filters must be used for AC inputs, and should be used for DC inputs.
1 2 3 4 5 6 7 8
O
N
IP7- - - - - - - - - - - - - - - - - IP0
THROUGH
IP47- - - - - - - - - - - - - - - - IP40
Filter Switch Banks FL1 FL6
Set Switch UP (ON) to Enable a Filter
(Shown all Enabled)
Figure 3. AC input filter switches FL1 to FL6
Unless you have reason to turn off a filter, you should enable it (switch up). With the filter on, an AC voltage
within the specified frequency range present on the input produces a constant high signal to the opto-isolator.
With the filter ON, an AC voltage on the input produces a DC voltage.
Note : To change the configuration of a switch on FL1 to FL3, you need to remove the board's protective shield.