DMM-16R-AT User Manual V1.31 www.diamondsystems.com Page 9
4.4 J5: D/A Configuration
The 4 D/A channels can be configured in two ways:
The full-scale output range can be selected between a fixed +5V output range or a user-programmable
output range. The programmable range can be set anywhere between 1V and 10V.
The outputs can be configured for unipolar (positive voltages only) or bipolar (both negative and positive
output voltages). In unipolar mode, the outputs range from 0V minimum to the selected full-scale voltage
(e.g. 5V in the fixed range). In bipolar mode, the outputs can range from – full-scale voltage to + full-scale
voltage (e.g. +/-5V in the fixed range). Note that the maximum swing in bipolar mode is equal in both
directions.
Two jumpers in J5 are used to configure the D/A channels. For fixed range, install a jumper in the location
marked 5. For programmable range, install a jumper in the location marked P. Do not install a jumper in both
locations simultaneously or across the two columns, as unpredictable behavior may result.
For bipolar inputs, install a jumper in the B location. For unipolar inputs, install a jumper in the U location. Do
not install a jumper in both locations simultaneously or across the two columns, as unpredictable behavior
may result.
Both the range and polarity jumpers must be installed for proper analog output behavior.
4.5 Interrupt Level Selection (for ISA bus interface only)
Jumper block J6 is used to configure interrupt level for ISA bus operation.
Interrupts are used to transfer data from the board to memory at a rate higher than that can be achieved
through software sampling. During interrupt operation, the board will periodically generate an interrupt
request. The processor will respond and run a user-supplied interrupt routine function (or the function
supplied with the board’s driver software). The interrupt routine reads the data from the board and makes it
available to the user application program.
DMM-16R-AT allows you to select from levels 15, 14, 12, 11, 10, 9, 7, 6, 5, 4, and 3. Only one IRQ level is
used by DMM-16R-AT. To select the desired IRQ level install a jumper in that number’s location in the
Interrupt area of jumper block J6.
On the PC/104 bus each IRQ level in use must have a 1K pull-down resistor attached. To enable the pull-
down resistor for this board, install a jumper in the R location on J6.
Typically, each peripheral board in a PC/104 system will use a different interrupt level, or IRQ level. However,
in special circumstances multiple boards may share the same IRQ level. In this case only one board should
have the pull-down resistor enabled with the R jumper. The other boards should not have the resistor
enabled.