Digital input/output wire connection
The DO and DI in the I-7242D are used for Modbus communication alarm.
If the number of Modbus communication error exceeds 100, the DO value will
be set as 1. And the DO status is OFF. Users can apply this to have a clear
warning. Then users can clear the alarm signal by setting the DI value as 0.
After setting the DI to ON state, the data lose counter of each device
would be adjusted to zero. The wire connection of digital input is as figure 2-6.
Digital Input level
Logical level 0: closed to GND
Logical level 1: open
Logical level 0: +1V
Logical level 1: +3.5V to +30V
I-7242D DeviceNet/Modbus RTU Gateway User's Manual, July 2006, Version 1.1
Figure 2-6 Digital Input Wire Connection
I-7242D user manual