| Model |
1794-IR8 |
| Number of Inputs |
8 channels |
Module Location
|
Cat. No. 1794-TB2, -TB3, -TB3S, -TB3T and -TB3TS Terminal Base Units |
| Nominal Input Ranges |
1 to 433 ohms |
| Resolution |
16 bits across 435 ohms |
| Common Mode Rejection |
-120db @ 60Hz; -100db @ 50Hz with A/D filter cutoff @ 10Hz |
Common Mode Input Range
|
0V between channels (common return) |
| Isolation Voltage |
Tested at 850V dc for 1s from inputs and user power to logic side |
| Data Format |
16-bit 2 s complement or offset binary (unipolar) |
| Normal Mode Noise Rejection |
-60db @ 60Hz for A/D filter cutoff @ 10Hz |
| Input Offset Drift w/Temperature |
1.5 milliohm/?C maximum |
| Gain Drift w/Temp. |
Normal mode: 20ppm/?C max.
Enhanced mode: 10ppm/?C max. |
Channel Bandwidth
|
0-2.62Hz (-3db) |
| Settling time to 100% of final value |
Available at system throughput rate |
| System Throughput
|
Normal mode – 325ms (1 channel scanned), programmable to 28ms 2.6s (8 channels scanned), programmable to 224ms
Enhanced mode – programmable from 56 to 650ms/channel – 650ms (1 channel scanned), 2.925s (8 channels scanned) |
| Open TC/RTD Circuit Detection |
Out of range reading (upscale) |
| Open TC/RTD Detection Time |
Available at system throughput rate |
| Overvoltage Capability |
35V dc, 25V ac continuous at 25?C |
| Overall Drift with Temperature |
50ppm/?C of span (maximum) |
| Cold Junction Compension
|
Range: 0 to 70?C
A-B catalog number 1794-CJC2 |
| Channel to channel isolation |
0V |
| Indicators |
1 red/green power status indicator |
| Flexbus Current |
20mA |
| Power Dissipation |
3.0W maximum @ 31.2V dc |
| Thermal Dissipation |
Maximum 10.2 BTU/hr @ 31.2V dc |
| Keyswitch Position |
3 |