Rockwell Automation 1791-IOBB USER MANUAL - Manual (Page 8)

Introducing Block I/O
Chapter 1
1Ć2
Wiring Connectors – Remote I/O link connector and input/output
connector are removable for easy connection of wiring.
Switch Assemblies – Two DIP switches are provided for setting the I/O
rack number, starting I/O group, transmission rate, last chassis, last state
and DH–485 terminator.
Status Indicators – LED indicators display the status of communication,
power and input/output. These provide a visual indication for aid in
troubleshooting.
DH–485 Port – A plug–in DH–485 data port is provided for use with the
SLC controller.
Block I/O is a complete I/O interface that includes the functionality of the
I/O rack, adapter, power supply, and I/O modules in a single unit. Connect
sensors and actuators to the module and use the remote I/O cable to
connect the block I/O to your programmable controller as shown in
chapter 2.
The block uses sinking inputs and sourcing outputs.
In sinking inputs (Figure 1.2), the dc common is bussed on the block. and
the current is sourced from the field device. The sourcing field device
switches the hot side of the power supply bus causing current to flow
through the sourcing device to the sinking input on the block.
Figure 1.2
Sinking Input Example
DC Power
Supply
Field
Device
Field
Device
Sinking
Input
COM
+V
-V
10826-I
Block I/O
How Block I/O Fits in a PLC
System