Rockwell Automation 1791-I0VW USER MANUAL - Manual (Page 8)

Introducing Block I/O
Chapter 1
1-3
Status Indicators - Bi-color LED indicators provide power, active,
communication and fuse blown indications. An LED array provides
input/output status.
Indicator Indication
Power (green/wht)
On (green) Customer voltage is present
Power (green/wht)
Off (wht) No customer voltage
Active (green/red)
On (green) CPU operating correctly
Active (green/red)
Off (red) CPU not running
Comm (green/wht)
On (green) Communication correctly established
Comm (green/wht)
Off (wht) Communication not established
Fuse (red/wht)
On (red) One of the fuses is open
Fuse (red/wht)
Off (wht) Both fuses are intact
The I/O status array is an 8 by 8 array of 64 LEDs capable of displaying
the status of 32 inputs and 32 outputs at any one time.
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. Simply
connect sensors and actuators to the module and use the remote I/O cable
to connect the block I/O to your programmable controller (Figure 1.6).
The 1791-IOBW block uses sinking inputs and sourcing outputs.
In sinking inputs, 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. Refer to Figure 1.2.
How the Block I/O Fits in a
PLC System