Devicelogix programming, Devicelogix programming example – Rockwell Automation 284E ArmorStart with EtherNet/IP - User Manual User Manual

Page 308

Advertising
background image

308

Rockwell Automation Publication 280E-UM001B-EN-P – July 2012

Appendix C Using DeviceLogix

• If the Network Override is enabled and the logic is enabled then

DeviceLogix controls the state of the outputs when the PLC is in Run
mode and if a network fault such as Duplicate MAC ID or module Bus off
condition occurs.

• If the Communications Override is enabled and the logic is enabled, the

device does not need any I/O connection to run the logic. As long as there
is control power and a DeviceNet power source connected to the device,
the logic will control the state of the outputs.

DeviceLogix Programming

DeviceLogix has many applications and the implementation is typically only
limited to the imagination of the programmer. Keep in mind that the application
of DeviceLogix is only designed to handle simple logic routines.

DeviceLogix is programmed using simple Boolean math operators such as AND,
OR, NOT, timers, counters, and latches. Decision making is done by combining
these Boolean operations with any of the available I/O. The inputs and outputs
used to interface with the logic can come from the network or from the device
hardware. Hardware I/O is the physical Inputs and Outputs located on the device
such as push buttons and pilot lights that are connected to the ArmorStart.

There are many reasons to use the DeviceLogix functionality, but some of the
most common are listed below:

• Increased system reliability
• Fast update times (1 - 2 ms possible)
• Improved diagnostics and reduced troubleshooting
• Operation independent of PLC or network status
• Continue to run process in the event of network interruptions
• Critical operations can be safely shutdown through local logic

DeviceLogix Programming
Example

The following example will show how to program a simple logic routine to
interface the ArmorStart EtherNet I/P with a remote hard-wired startstop
station. In this case the I/O is wired as shown in

Table 51

.

Table 51 - Hardware Bit Assignments and Description for the ArmorStart

Input Table

Output Table

Bit

Description

Bit

Description

In 0

Start Button

Run Forward

Contactor Coil

In 1

Stop Button

N/A

N/A

In 2

N/A

In 3

N/A

Advertising