Rockwell Automation Allen-Bradley 1794-IRT8K, User Manual

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Publication 1794-6.5.12 - September 2011
54
Specifications
Isolation voltage
(continuous voltage
withstand rating)
50V (continuous), Basic Insulation Type
Type tested @ 1365V AC for 60 s, between field side
and system
No isolation between individual channels
System throughput (8
channels scanned) – Add
0.5 ms if filtering is
selected
Typical module timing is shown here.
7.4 ms - millivolt
8.0 ms -
Ω
- 2-wire RTD
10.0 ms - Ω - 3-wire RTD
10.4 ms -
Ω
- 4-wire RTD
8.0 ms - 2-wire RTD (°F)
10.4 ms - 4-wire RTD (°F)
8.8 ms - 2-wire RTD (°C), (°K)
10.8 ms - 4-wire RTD (°C), (°K)
9.8 ms - 3-wire RTD (°F)
10.0 ms - 3-wire RTD (°C), (°K)
9.0 ms - Thermocouples (°F)
9.4 ms - Thermocouples (°C), (°K)
Open circuit protection
RTD mode – Open input – Module defaults to max value
TC mode – Open input – Module defaults to min value
To simulate wire-off detection in Series A TC mode when using
a Series B module, attach a jumper from terminal 39 to terminal
48 on the 1794-TB3G, 1794-TB3GS, or 1794-TB3GK terminal
base unit so that an open input will default to max value.
Open input detection time Immediate detection 2 scans, max
Overvoltage capability 15V DC continuous at 25 °C
Overall drift with
temperature, max
50 ppm/°C of span
Cold junction
compensation range
-20…100 °C
Cold junction compensator Allen-Bradley catalog number 1794-CJC2
Indicators
1 green power status indicator
8 red open input indicators
FlexBus current 40 mA
Power dissipation, max 3.0 W @ 31.2V DC
Thermal dissipation, max 10.2 BTU/hr @ 31.2V DC
Keyswitch position 3
External DC power
supply voltage
Voltage range
Supply current
24V DC nom
95 mA @ 24V DC
Dimensions (with module
installed in base) HxWxD
approx.
94 x 94 x 69 mm
(3.7 x 3.7 x 2.7 in.)
Temperature code, IEC T4
General Specifications
Attribute Value