The Allen-Bradley 1756-DNB is a DeviceNet Scanner module that connects to a ControlLogix system. It serves as a bridge that collects data from the DeviceNet modules and then delivers a copy of the information to the controller and vice versa. Using the 1756-DNB scanner module, the user can expect DeviceNet communication rates of 125 kilobytes per second by default, 250 kilobytes per second, and up to 500 kilobytes per second. It has DeviceNet node addresses 00 to 63, with node address 63 set by default and a maximum of 64 nodes. It is only compatible with the Logix5550 controller. This particular module acts as a gateway between DeviceNet devices and the network in order to read input and write output from a device, download the configuration data, and monitor the operational status of a device.
ManufacturerRockwell Automation
BrandAllen-Bradley
Part Number/Catalog No.1756-DNB
SeriesControlLogix
Module TypeScanner Module
DeviceNet Communication Rates125, 250, or 500 kilobites per second
LocationControlLogix Chassis (any slot)
Backplane Current (5Volts)580 milliamps
Backplane Current (24Volts)3 milliamps
Power Dissipation (Max)5.8 Watts
Thermal Dissipation19.8 BTU per hour
DeviceNet Current11-25 Volts DC
Insulation Voltage30 Volts Continuous
Operating Temperature0-60 Celsius (32-140 Fahrenheit)
The Allen-Bradley 1756-DNB will communicate in the form of Diagnostic Tables, Inputs, and Outputs when the controller is involved. The I/O’s exchange configuration data, status information, and the I/O data of the device. The module communicates using strobe, poll, change of state, and/or cyclic messages with another device. These messages are used to gather from or deliver data to every device. The data received from a device will then be organized and made available to the controller (input data) and the data received from the controller will be sent to the device (output data). The 1756-DNB's current draw at 5.1 Volts DC is 400 milliamps while it stays at 0 milliamps when the current draw is at 24 Volts DC. The power dissipation of this module is around 3.5 Watts and its thermal dissipation is at 11.9 BTU/hour. This module can be installed in any available chassis slot and is used together with the RSNetWorx.