Allen-Bradley 1769-SDN, Installation Instructions Manual, Page: 52 / 68

52 Rockwell Automation Publication DNET-IN001B-EN-P - January 2012
Appendix A 1756 DeviceNet Status Indicators and Data Structures
Input Structure
The controller receives input I/O by reading input data from an input structure
in the 1756-DNB scanner module. The scanner module receives input data from
DeviceNet modules and delivers a copy of these values to the controller. The
input structure consists of one 32-bit status register and a variable size 32-bit array
of up to 124 words for input data. The 32-bit status register reflects the current
state of several key module-level operational parameters.
The input structure consists of these data elements.
Output Structure
The controller controls output I/O by writing output data to an output structure
in the 1756-DNB scanner module. The scanner module then delivers a copy of
these output values to modules on the DeviceNet network. The output structure
consists of a 32-bit command register and a variable size 32-bit array of up to 123
words for output data. The 32-bit command register consists of several bits that
affect the module’s behavior on the network.
The output structure consists of these data elements.
Module Command Register Bit Definitions
The bits of the Module Command Register are defined as follows.
Input Structure Element Data Type
module status register 1 x 32-bit register
input_data 123 x 32-bit variable size data array
Output Structure Element Data Type
module command register 1 x 32-bit register
output_data 123 x 32-bit data array
Bit Name Description
0 Run 1 = Run mode
0 = Idle mode
1 Fault 1 = Fault network
2 DisableNetwork 1 = Disable network
3 HaltScanner 1 = Halt module
The 1756-DNB scanner module ceases all operation.
4 Reset 1 = Reset module (put back to 0 to resume operation)
5…31 Reserved Unused