Allen-Bradley 1756-IA32 - Review of Tags in Ladder Logic

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 231
Use Ladder Logic To Perform RunTime Services and Reconfiguration Appendix C
The table defines the values returned for each rung.
Review of Tags in Ladder Logic
When you use tags in ladder logic applications, remember these guidelines:
• Ladder logic tags represent the module on a point per bit basis. For
example, point 0 = bit 0 on the module.
• If you are performing a service through the tags, a value of 0 prevents the
action from occurring, and a value of 1 causes the action to occur. For
example, if you want to reset the electronic fuse on a particular bit, enter 1
in the tags.
• If you are checking the response of a service through the tags, a value of 0
means the bit passed the service, and a value of 1 means the bit failed the
service. For example, if you perform a pulse test and the response displays a
0 for a particular bit, the bit passed the test.
Table 60 - Rung Values
Rung Module ID Retrieved Description
1 Product Type
Catalog Code
Module’s product type, 7=Digital I/O, 10=Analog I/O
Module’s catalog number
2 Major Revision
Minor Revision
Module’s major revision
Module’s minor revision
3 Status Module’s status. Multiple bits listed.
Bit 0: 0 = Unowned, 1 =Owned
Bit 1: Reserved
Bit 2: 0 = Unconfigured, 1 = Configured
Bit 3: Reserved
Bits 7-4: Forms a 4-bit number indicating Device Specific Status.
0 = Self-Test
1 = Flash update in progress
2 = Communications fault
3 = Not owned (outputs in Program mode)
4 = Unused
5 = Internal fault (need flash update)
6 = Run mode
7 = Program mode (output mods only)
Bit 8: 0 = No fault, 1 = Minor recoverable fault
Bit 9: 0 = No fault, 1 = Minor recoverable fault
Bit 10: 0 = No fault, 1 = Minor recoverable fault
Bit 11: 0 = No fault, 1 = Major unrecoverable fault
Bits 15…12: Unused
4 Vendor ID
Serial Number
Module manufacturer vendor, 1 = Allen-Bradley
Module serial number
5 Length of ASCII Text String
ASCII Text String
Number of characters in module’s text string
Module’s ASCII text string description