Digital Inputs

Input bits are arranged in a group of 4 and share a common pin (INCOM, PIN-7, located on the Auxiliary I/O connector). This lets a group be connected to current sourcing or current sinking devices, based on the connection of the common pin.

To be able to connect an input group to current sourcing devices, connect the common pin to the power supply return (-). Refer to Digital Inputs Connected to Current Sourcing (PNP) Devices .

To be able to connect an input group to current sinking devices, connect the common pin to the power supply source (+). Refer to Digital Inputs Connected to Current Sinking (NPN) Devices .

The digital inputs are not designed for high-voltage isolation applications. They should only be used with ground-referenced circuits.

Table 2-15:     Digital Input Specifications

Input Voltage	Approximate Input Current	Turn On Time	Turn Off Time
+5 V to +24 V	6 mA	10 µs	43 µs

Table 2-16:     Digital Input Pins on the I/O "B" Connector

Pin #	Label	Description	In/Out/Bi
1	DI0	Digital Input 0 (Optically-Isolated)	Input
2	DI1	Digital Input 1 (Optically-Isolated)	Input
3	DI2	Digital Input 2 (Optically-Isolated)	Input
4	DI3	Digital Input 3 (Optically-Isolated)	Input

Table 2-17:     Digital Input Pin on the Auxiliary I/O Connector

Pin #	Label	Description	In/Out/Bi
7	INCOM	Digital Input Common	Input

Figure 2-5:     Digital Inputs Schematic

Figure 2-6:     Digital Inputs Connected to Current Sourcing (PNP) Devices

 

Figure 2-7:     Digital Inputs Connected to Current Sinking (NPN) Devices