Product Description:

The 3DI475.6 digital input module is part of the System 2005 Controllers series from B & R Automation. It attaches to a System 2005 backplane and provides sixteen DC sensing channels that report field conditions to the CPU. By converting voltage levels from sensors, switches, or proximity devices into logic data, the card supports industrial automation tasks such as machine interlocks, safety guarding, and process monitoring.

Each channel has a nominal operating level of 24 VDC, and the board accommodates 16 inputs arranged in 4 electrically separated groups. The inputs in each group share a return line, while optocouplers provide isolation between the groups. An input resistance of 4.8 kΩ limits the current drawn from connected sensors. A typical propagation time of 10 ms allows the controller to detect signals from standard mechanical contacts without responding to brief contact chatter. A logic high is recognized when the terminal voltage exceeds 15 V, while a logic low is confirmed when the voltage falls below 5 V. The terminals can be wired in sink or source mode, allowing the module to support PNP or NPN field devices.

Under worst-case conditions, an on-off transition can have a maximum delay of 12 ms, which should be considered when calculating scan times. The input circuits are optically isolated from the PLC backplane, but individual points within each group are not isolated from one another. This arrangement should be considered when fast and slow sensors are connected within the same group. The circuitry tolerates continuous input levels up to 30 VDC and withstands transient peaks of 500 V without damage. Overall module power dissipation is limited to 1.5 W, allowing dense installation without separate heat sinks. Optocoupler isolation helps preserve signal integrity between the field inputs and the controller electronics while maintaining low power consumption.