Rockwell Automation 1755-OF8 GuardPLC Controller Systems - Manual (Page 251)

Publication 1753-UM001C-EN-P - March 2010 251
Use the GuardPLC Controller as a Scanner Chapter 20
Also make sure that the data to be written or read does not cross data
type boundaries or try to use only a portion of the signal. In the
example above, you must assign 1 WORD or 1 INT signal, or 2 BYTE
signals to the output assembly and 6 BYTES, or 3 WORDs, or 3 INT
signals to the input tab. If any I/O module uses an odd number of
bytes, then you must use only BYTE data type signals. For example,
the 1734-IB4 module requires 2.5 WORDs or 5 BYTEs for the input
assembly. If you use anything other than BYTE signals, the GuardPLC
returns an error to RSNetWorx for EtherNet/IP software when you try
to save the scanlist.
Disable Scanner Function on the Controller
The controller is able to function as a scanner by default. Follow these
steps if you need to disable scanner function.
1. Right-click EtherNet/IP in the project tree under the desired
Resource and choose Connect Signals to open the Signal
Connections dialog box.
2. To open the Signal Editor, from the Signals menu, choose Editor.
3. Create a new signal of type BOOL and an initial value of 1.
TIP
The GuardPLC controller uses four input bytes for status. To
prevent this data from automatically being the first four data
signals, add four BYTE signals to the first 4 rows of the Inputs
tab. In RSNetWorx for EtherNet/IP software, offset 0 will be
TAG_000, as shown below.