Analog Input Dc Voltage Measurement Accuracy; Digital Input/Output - Omega OMB-AI-EXP32 User Manual

OMB-AI-EXP32 User's Guide

Analog input DC voltage measurement accuracy

The OMB-AI-EXP32 is a multiplexer-based channel expansion module that increases the number of voltage
input channels of a OMB-DAQ-2416 series host module. For voltage accuracy information, refer to the
electrical specification of the OMB-DAQ-2416 host device that is the interface to the OMB-AI-EXP32
interface.

Digital input/output

Number of I/O
Configuration
Input voltage range
Input type
Input characteristics
Maximum input voltage range
Pull-up/pull-down configuration
Transfer rate (software paced)
Input high voltage
Input low voltage
Schmitt trigger hysteresis
DGND pins (pins 29, 30, 61, 62) are recommended for use with digital input and digital output pins.
Note 1:
The DGND and GND pins are common and are isolated from earth ground.
Number of I/O
Configuration
Output characteristics
Pull-up configuration
Transfer rate (software paced)
Output voltage range
Drain to source breakdown voltage
Off state leakage current (Note 5)
Sink current capability
DMOS transistor on-resistance
(drain to source)
Each DMOS transistor's source pin is internally connected to GND.
Note 2:
Note 3: DGND pins (pins 29, 30, 61, 62) are recommended for use with digital input and digital output pins.
The DGND and GND pins are common and are isolated from earth ground.
Note 4: The external pull-up is connected to the digital output bit through an external pull-up resistor. Adding
an external pull-up resistor connects it in parallel with the internal 47k Ω pull-up resistor of that
particular digital input/output bit. Careful consideration should be made when considering the external
pull-up resistor value and the resultant pull-up voltage produced at the load.
Table 5. Digital input specifications
16 channels
Each DIO bit can be independently read from (DIN) or written to (DOUT).
The DIN bits can be read at any time whether the DOUT is active or tri-stated.
0 to +15 V
CMOS (Schmitt trigger)
47 kΩ pull-up/pull-down resistor, 28 kΩ series resistor
0 to +20 V maximum (power on/off, relative to DGND pins 29,30,61,62)
All pins pulled up to +5 V via individual 47 kΩ resistors.
The JP1 (DIO 8- 15) shorting block default position is pull-up or "HI."

The JP2 (DIO 16- 23) shorting block default position is pull-up or "HI."

Pull down capability is available by placing either of the JP1 and JP2 shorting
blocks in the "LO" position.
500 port reads or single-bit reads per second, typical.
1.3 V minimum, 2.2 V maximum
1.5 V maximum, 0.6 V minimum
0.4 V minimum, 1.2 V maximum
Table 6. Digital output specifications
16 channels
Each DIO bit can be independently read from (DIN) or written to (DOUT).
The DIN bits may be read at any time whether the DOUT is active or tri-stated
47 kΩ pull-up, open drain (DMOS transistor)
All pins pulled up to +5 V via individual 47 kΩ resistors.
The JP1 (DIO 8- 15) shorting block default position is pull-up or "HI."

The JP2 (DIO 16- 23) shorting block default position is pull-up or "HI."

Digital output – 500 port writes or single-bit writes per second typical.
0 to +5 V (no external pull up resistor, internal 47 kΩ pull-up resistors

connected to +5 V by default)
0 to +15 V maximum (Note 4)

+50 V minimum
0.1 µA
150 mA maximum (continuous) per output pin

150 mA maximum (continuous) for all eight channels

4 Ω
13
Specifications