| Width | 45 mm (1.77”) |
| Depth | 102 mm (4.01”), 111 mm (4.37”) including connector |
| Height | 119 mm (4.7”) |
| Weight | 0.2 kg (0.44 lbs.) |
The AI820 analog input module has 4 differential bipolar current/voltage inputs. Each channel can be a voltage or current input. The current input can withstand unexpected maximum normal mode 30 V DC connections. To protect the current input circuit from dangerous input levels, i.e. accidental connection to a 24 V supply, the 250W current detection resistor is rated at about 5 watts. This is only used to temporarily secure one channel at a time.
This module allocates external transmitter power to each channel. This adds a simple connection (with an extended MTU) to distribute power to an external 2-wire transmitter. There is no current limit on the transmitter power terminal.
All 4 channels are isolated from the ModuleBus as a group. The power supply of the input stage is converted from 24 V on the ModuleBus.
Characteristics and advantages
4 channels for -20… +20 mA, 0… 20 mA, -10… +10 V, 0… 10 V, 2… 10 V, -5… +5 V, 0… 5 V, 1… 5 V DC bipolar differential input
A group of 4 channels, isolated from the ground
14-bit resolution plus sign
Input shunt resistor protects to 30 V DC
The input accepts HART communication