Omega OM-USB-1208HS Series, Руководство пользователя

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OM-USB-1208HS Series User's Guide Functional Details
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Each channel can be software-paced at rates up to 5,000 updates per second (system-dependent), or hardware-
paced at rates up to 1 MS/s.
Each analog output on the OM-USB-1208HS-2AO and OM-USB-1208HS-2AO has a fixed ±10 V output
range. The outputs default to 0 V at power up.
External clock I/O
Use the
AICKI
and
AOCKI
terminals to receive a sampling clock from an external source.
Use the AICKO terminal to output the internal A/D sampling clock. Use the AOCKO terminal to output the
internal D/A sampling clock. When using an external clock, a pulse output generated by the external clock
rising edge is also available at these terminals.
Refer to Figure 3 on page 11 for the location of these pins.
Digital I/O
You can connect up to 16 digital I/O lines to screw terminals DIO0 through DIO15 . Refer to Figure 3 on page 11
for the location of these pins.
The 16 DIO terminals have 47 k resistors that you can configure for pull-up/pull-down using a jumper inside the
case. The default configuration is pull-down.
You can use the digital I/O terminals to detect the state of any TTL-level input. Refer to the schematic shown in
Figure 5.
Figure 5. Schematic showing switch detection by digital channel DIO0
If you set the switch to the +5 V input, DIO0 reads TRUE (1). If you move the switch to GND, DIO0 reads
FALSE (0).
Internal pull-up/pull-down capability
Each of the 16 DIO bits on the has a 47 kΩ pull-up/pull-down resistor. To configure these bits for either a +5 V
pull-up or a 0 V pull-down option, you must open the device case to access the three-pin jumper labeled
W34 .
The pull-up/pull-down voltage is common to all of the internal 47 kΩ resistors.
To open the case and set the W34 jumper, do the following.
1. Turn the device over and rest the top of the housing on a flat, stable surface.
2. Peel off the four rubber feet on the bottom of the device to access the screws.
3. Remove the four screws from the bottom of the device.
4. Hold both the top and bottom sections together, turn the device over and rest it on the surface, then
carefully remove the top section of the case to expose the circuit board.
5. Configure jumper W34 for either pull-up or pull-down. The jumper is configured by default for pull-down
(see Figure 6 and Figure 7).