Digital I/O Specifications
Digital I/O specifications are described in the following tables.
Table 26: Digital Input Specifications
Unit
Maximum
Minimum
Specification
Volts
60
2.2
Input Voltage High
Volts
1.2
—
Input Voltage Low
mA
0.68mA
—
Input Current
Current is flowing out of the terminal although it is an input, that is, sourcing. The current is flowing in the
terminal for the output, that is, sinking.
Note
Table 27: Digital Output Specifications
Notes
Unit
Maximum
Minimum
Specification
No external voltage applied.
Volts
—
2.5
Output Voltage High
No external voltage applied.
Volts
0.4
—
Output Voltage Low
—
Ohms
1K – 1%
1K – 1%
Internal Pull-Up Resistance
—
Volts
3
—
Internal Pull-Up Voltage
External resistance required to limit current to 200mA.
Volts
60
3.3
External Pull-Up Voltage
—
mA
200
—
Sink Current
Controller Area Network Bus Features
The IR1800 features support for the Controller Area Network (CAN) Bus interface through two wires that
connect to the OBD-II connector of the vehicle.
The following are some of the characteristics of the CAN Bus:
• CAN Bus enables the ECU (electronic control unit) in a vehicle to communicate with all other ECUs
• Consists of two wires: CAN Bus High and Low, supporting data rate up to 1 Mbs
• High-speed CAN Bus 2.0B: ISO 11898-1 data link layer, ISO 11898-2 and ISO-11898-5 physical layer
up to 1 Mbs data rate (software dependent)
• Maximum cable length between 500 m (125 kbit/s) and 40 m (1 Mbit/s)
• 120-ohms CAN Bus termination
Cisco Catalyst IR1800 Rugged Series Router Hardware Installation Guide
75
Digital I/O, Ignition, and CAN Bus Connectivity
Digital I/O Specifications