Temperature Alarms; Counter; Memory - Omega OM-USB-TC-AI User Manual

OM-USB-TC-AI User's Guide

Temperature alarms

Parameter
Number of alarms
Alarm functionality
Alarm input modes
Alarm output modes
Alarm update rate

Counter

Parameter
Pin name
Number of channels
Resolution
Counter type
Input type
Input source
Counter read/writes rates
(software paced)
Schmidt trigger hysteresis
Input leakage current
Input frequency
High pulse width
Low pulse width
Input high voltage
Input low voltage
All ground pins are common and are isolated from earth ground. If a connection is made to earth
Note 13:
ground with both the counter (CTR) and conductive thermocouples, the thermocouples are no longer
isolated. In this case, thermocouples must not be connected to any conductive surfaces that may be
referenced to earth ground.

Memory

Parameter
EEPROM
Table 12. Temperature alarm specifications
Specification
8 (one per digital I/O line)
Each alarm controls its associated digital I/O line as an alarm output. The input to each
alarm may be any of the analog temperature input channels. When an alarm is enabled, its
associated I/O line is set to output (after the device is reset) and driven to the appropriate
state determined by the alarm options and input temperature. The alarm configurations are
stored in non-volatile memory and are loaded at power on. Alarms will function both in
data logging mode and while attached to USB.
Alarm when input temperature > T1

Alarm when input temperature > T1, reset alarm when input temperature goes below T2

Alarm when input temperature < T1

Alarm when input temperature < T1, reset alarm when input temperature goes above T2

Alarm when input temperature is < T1 or > T2

Note: T1 and T2 may be independently set for each alarm.
Disabled, digital I/O line may be used for normal operation

Enabled, active high output (digital I/O line goes high when alarm conditions met)

Enabled, active low output (digital I/O line goes low when alarm conditions met)

1 second
Table 13. CTR I/O specifications
Specification
CTR
1
32-bits
Event counter
TTL, rising edge triggered
CTR screw terminal
Counter read: system dependent, 33 to 1000 reads per second.
Counter write: system dependent, 33 to 1000 reads per second.
20 mV to 100 mV
±1.0 µA typ
1 MHz max
500 nS min
500 ns min
4.0 V min, 5.5 V absolute max
1.0 V max, –0.5 V absolute min
Table 14. Memory specifications
Specification
1,024 bytes isolated micro reserved for sensor configuration
256 bytes USB micro for external application use
22
Specifications